土木工程英文翻译

外文文献及译文

文献、资料题目：PROTECTION AGAINST HAZARDS 院（部）：建筑工程学院

专业：土木工程

班级：土木081

姓名：孙继佳

学号：200811003192

指导教师：樊江

翻译日期：2012.5.4

3.1 PROTECTION AGAINST WA TER

Whether thrust against and into a building by a flood, driven into the interior by a heavy rain, leaking from plumbing, storm surge, or seeping through the exterior enclosure, water can cause costly damage to a building. Consequently, designers should protect buildings and their contents against water damage.

Protective measures may be divided into two classes: floodproofing and waterproofing.Floodproofing provides protection against flowing surface water, commonly caused by a river overflowing its banks. Waterproofing provides protection against penetration through the exterior enclosure of buildings of groundwater, rainwater,and melting snow. Buildings adjacent to large water bodies may also require protection from undermining due to erosion and impact from storm driven waves.

3.4.1Floodproo?ng

A ?ood occurs when a river rises above an elevation,called ?ood stage,and is not Prevented by enclosures from causing damage beyond its banks.Buildings con- Structed in a ?ood plain,an area that can be inundated by a ?ood,should be Protected against a ?ood with a mean recurrence interval of 100 years.Maps Showing ?ood-hazard areas in the United States can be obtained from the Federal InsuranceAdministrator,DepartmentofHousingandUrbanDevelopment,who Administers the National Flood Insurance Program.Minimum criteria for?ood-

proo?ng are given in National Flood Insurance Rules and Regulations(Federal Register, vol.41,no.207,Oct.26,1976).

Major objectives of ?oodproo?ng are to protect fully building and contents from Damage from a l00-year ?ood,reduce losses from more devastating ?oods,and Lower ?ood insurance premiums.Floodproo?ng,however,would be unnecessary if Buildings were not constructed in ?ood prone areas.Building in ?ood prone areas Should be avoided unless the risk to life is acceptable and construction there can

Be economically and socially justi?ed.

Some sites in flood prone areas possess some ground high enough to avoid flood damage. If such sites must be used, buildings should be clustered on the high areas. Where such areas are not available, it may be feasible to build up an earth fill, with embankments protected against erosion by water, to raise structures above flood levels. Preferably, such structures should not have basements, because they would require costly protection against water pressure.

An alternative to elevating a building on fill is raising it on stilts (columns in

an unenclosed space). In that case, utilities and other services should be protected against damage from flood flows. The space at ground level between the stilts may

be used for parking automobiles, if the risk of water damage to them is acceptable

or if they will be removed before flood waters reach the site.

Buildings that cannot be elevated above flood stage should be furnished with an impervious exterior. Windows should be above flood stage, and doors should seal tightly against their frames. Doors and other openings may also be protected with

a flood shield, such as a wall. Openings in the wall for access to the building may be protected with a movable flood shield, which for normal conditions can be stored

out of sight and then positioned in the wall opening when a flood is imminent.

To prevent water damage to essential services for buildings in flood plains, important mechanical and electrical equipment should be located above flood level. Also, auxiliary electric generators to provide some emergency power are desirable.

In addition, pumps should be installed to eject water that leaks into the building. Furthermore, unless a building is to be evacuated in case of flood, an emergency water supply should be stored in a tank above flood level, and sewerage should be provided with cutoff valves to prevent backflow.

3.4.2 W aterproofing

In addition to protecting buildings against floods, designers also should adopt measures that prevent groundwater, rainwater, snow, or melted snow from penetrating into the interior through the exterior enclosure. Water may leak through cracks, expansion joints or other openings in walls and roofs, or through cracks around windows and doors. Also, water may seep through solid but porous exterior materials, such as masonry. Leakage generally may be prevented by use of weatherstripping around windows and doors, impervious waterstops in joints, or calking of

cracks and other openings. Methods of preventing seepage, however, depend on the types of materials used in the exterior enclosure.

Definitions of Terms Related to Water Resistance

Permeability. Quality or state of permitting passage of water and water vapor

into, through, and from pores and interstices, without causing rupture or displacement. Terms used in this section to describe the permeability of materials, coatings, structural elements, and structures follow in decreasing order of permeability: Pervious or Leaky. Cracks, crevices, leaks, or holes larger than capillary pores, which permit a flow or leakage of water, are present. The material may or may

not contain capillary pores.

W ater-resistant. Capillary pores exist that permit passage of water and water vapor, but there are few or no openings larger than capillaries that permit leakage

of significant amounts of water.

W ater-repellent. Not ‘‘wetted’’ by w ater; hence, not capable of transmitting water

by capillary forces alone. However, the material may allow transmission of water under pressure and may be permeable to water vapor.

W aterproof. No openings are present that permit leakage or passage of water and water vapor; the material is impervious to water and water vapor, whether under pressure or not.

These terms also describe the permeability of a surface coating or a treatment against water penetration, and they refer to the permeability of materials, structural members, and structures whether or not they have been coated or treated. Permeability of Concrete and Masonry. Concrete contains many interconnected voids and openings of various sizes and shapes, most of which are of capillary dimensions. If the larger voids and openings are few in number and not directly connected with each other, there will be little or no water penetration by leakage

and the concrete may be said to be water-resistant.

Concrete in contact with water not under pressure ordinarily will absorb it. The

water is drawn into the concrete by the surface tension of the liquid in the wetted capillaries.

Water-resistant concrete for buildings should be a properly cured, dense, rich concrete containing durable, well-graded aggregate. The water content of the concrete mix should be as low as is compatible with workability and ease of placing

and handling. Resistance of concrete to penetration of water may be improved, however, by incorporation of a water-repellent admixture in the mix during manufacture.

(See also Art. 9.9.)

Water-repellent concrete is permeable to water vapor. If a vapor-pressure gradient

is present, moisture may penetrate from the exposed face to an inner face.

The concrete is not made waterproof (in the full meaning of the term) by the use

of an integral water repellent. Note also that water repellents may not make concrete impermeable to penetration of water under pressure. They may, however, reduce absorption of water by the concrete.

Most masonry units also will absorb water. Some are highly pervious under pressure. The mortar commonly used in masonry will absorb water too but usually contains few openings permitting leakage.

Masonry walls may leak at the joints between the mortar and the units, however. Except in single-leaf walls of highly pervious units, leakage at the joints results

from failure to fill them with mortar and poor bond between the masonry unit and mortar. As with concrete, rate of capillary penetration through masonry walls is small compared with the possible rate of leakage.

Capillary penetration of moisture through above-grade walls that resist leakage

of wind-driven rain is usually of minor importance. Such penetration of moisture

into well-ventilated subgrade structures may also be of minor importance if the moisture is readily evaporated. However, long-continued capillary penetration into some deep, confined subgrade interiors frequently results in an increase in relative humidity, a decrease in evaporation rate, and objectionable dampness.

3.4.3 Roof Drainage

Many roof failures have been caused by excessive water accumulation. In most cases, the overload that caused failure was not anticipated in design of those roofs, because the designers expected rainwater to run off the roof. But because of inadequate

drainage, the water ponded instead.

On flat roofs, ponding of rainwater causes structural members to deflect. The resulting bowing of the roof surface permits more rainwater to accumulate, and the additional weight of this water causes additional bowing and collection of even

more water. This process can lead to roof collapse. Similar conditions also can

occur in the valleys of sloping roofs.

To avoid water accumulation, roofs should be sloped toward drains and pipes

that have adequate capacity to conduct water away from the roofs, in accordance

with local plumbing codes. Minimum roof slope for drainage should be at least 1?4

in / ft, but larger slopes are advisable.

The primary drainage system should be supplemented by a secondary drainage system at a higher level to prevent ponding on the roof above that level. The overflow drains should be at least as large as the primary drains and should be connected to drain pipes independent of the primary system or scuppers through

the parapets. The roof and its structural members should be capable of sustaining

the weight of all rainwater that could accumulate on the roof if part or all of the primary drainage system should become blocked.

3.4.4 Drainage for Subgrade Structures

Subgrade structures located above groundwater level in drained soil may be in contact with water and wet soil for periods of indefinite duration after longcontinued rains and spring thaws. Drainage of surface and subsurface water, however,

may greatly reduce the time during which the walls and floor of a structure

are subjected to water, may prevent leakage through openings resulting from poor workmanship and reduce the capillary penetration of water into the structure. If subsurface water cannot be removed by drainage, the structure must be made waterproof or highly water-resistant.

Surface water may be diverted by grading the ground surface away from the

walls and by carrying the runoff from roofs away from the building. The slope of

the ground surface should be at least 1?4 in / ft for a minimum distance of 10 ft from the walls. Runoff from high ground adjacent to the structure should also be diverted. Proper subsurface drainage of ground

water away from basement walls and

floors requires a drain of adequate size,

sloped continuously, and, where necessary,

carried around corners of the building

without breaking continuity. The

drain should lead to a storm sewer or to

a lower elevation that will not be

flooded and permit water to back up in

the drain.

Drain tile should have a minimum diameter

of 6 in and should be laid in

gravel or other kind of porous bed at

least 6 in below the basement floor. The

open joints between the tile should be

covered with a wire screen or building

paper to prevent clogging of the drain

with fine material. Gravel should be laid above the tile, filling the excavation to an elevation well above the top of the footing. Where considerable water may be expected in heavy soil, the gravel fill should be carried up nearly to the ground surface and should extend from the wall a distance of at least 12 in (Fig. 3.7).

3.4.5 Concrete Floors at Grade

Floors on ground should preferably not be constructed in low-lying areas that are

wet from ground water or periodically flooded with surface water. The ground should

slope away from the floor. The level of the finished floor should be at least

6 in above grade. Further protection against ground moisture and possible flooding

of the slab from heavy surface runoffs may be obtained with subsurface drains located at the elevation of the wall footings.

All organic material and topsoil of poor bearing value should be removed in preparation of the subgrade, which should have a uniform bearing value to prevent unequal settlement of the floor slab. Backfill should be tamped and compacted in layers not exceeding 6 in in depth.

Where the subgrade is well-drained, as where subsurface drains are used or are unnecessary, floor slabs of residences should be insulated either by placing a granular fill over the subgrade or by use of a lightweight-aggregate concrete slab covered

with a wearing surface of gravel or stone concrete. The granular fill, if used, should have a minimum thickness of 5 in and may consist of coarse slag, gravel, or crushed stone, preferably of 1-in minimum size. A layer of 3-, 4-, or 6-in-thick hollow masonry building units is preferred to gravel fill for insulation and provides a smooth, level bearing surface.

Moisture from the ground may be absorbed by the floor slab. Floor coverings,

such as oil-base paints, linoleum, and asphalt tile, acting as a vapor barrier over

the slab, may be damaged as a result. If such floor coverings are used and where

a complete barrier against the rise of moisture from the ground is desired, a twoply bituminous membrane or other waterproofing material should be placed beneath

the slab and over the insulating concrete or granular fill (Fig. 3.8). The top of the lightweight-aggregate concrete, if used, should be troweled or brushed to a smooth level surface for the membrane. The top of the granular fill should be covered with

a grout coating, similarly finished. (The grout coat, 1?2 to 1 in thick, may consist

of a 1:3 or a 1:4 mix by volume of portland cement and sand. Some 3?8- or 1?2-in maximum-sized coarse aggregate may be added to the grout if desired.) After the

top surface of the insulating concrete or grout coating has hardened and dried, it should be mopped with hot asphalt or coal-tar pitch and covered before cooling

with a lapped layer of 15-lb bituminous saturated felt. The first ply of felt then should be mopped with hot bitumen and a second ply of felt laid and mopped on

its top surface. Care should be exercised not to puncture the membrane, which completion.

If properly laid and protected from damage, the membrane may be considered

to be a waterproof barrier.

Where there is no possible danger of water reaching the underside of the floor,

a single layer of 55-l

b smooth-surface asphalt roll roofing or an equivalent waterproofing

membrane may be used under the floor. Joints between the sheets should

be lapped and sealed with bituminous mastic. Great care should be taken to prevent puncturing of the roofing layer during concreting operations. When so installed, asphalt roll roofing provides a low-cost and adequate barrier against the movement

of excessive amounts of moisture by capillarity and in the form of vapor. In areas with year-round warm climates, insulation can be omitted.

(‘‘A Guide to the Use of Waterproofing, Dampproofing, Protective and Decorative Barrier Systems for Concrete,’’ ACI 515.1R, American Concrete Institute.)

3.4.6 Basement Floors

Where a basement is to be used in drained soils as living quarters or for the storage

of things that may be damaged by moisture, the floor should be insulated and should preferably contain the membrane waterproofing described in Art. 3.4.5 In general

the design and construction of such basement floors are similar to those of floors

on ground.

If passage of moisture from the ground into the basement is unimportant or can

be satisfactorily controlled by air conditioning or ventilation, the waterproof membrane need not be used. The concrete slab should have a minimum thickness

of 4 in and need not be reinforced, but should be laid on a granular fill or other insulation placed on a carefully prepared subgrade. The concrete in the slab should have a minimum compressive strength of 2000 psi and may contain an integral

water repellent.

A basement floor below the water table will be subjected to hydrostatic upward pressures. The floor should be made heavy enough to counteract the uplift.

An appropriate sealant in the joint between the basement walls and a floor over drained soil will prevent leakage into the basement of any water that may occasionally accumulate under the slab. Space for the joint may be provided by use of

beveled siding strips, which are removed after the concrete has hardened. After the slab is properly cured, it and the wall surface should be in as dry a condition as is practicable before the joint is filled to ensure a good bond of the filler and to reduce the effects of slab shrinkage on the permeability of the joint.

(‘‘Guide to Joint Sealants for Concrete Structures,’’ ACI 504R, American Concrete Institute.)

3.4.7 Monolithic Concrete Basement W alls

These should have a minimum thickness of 6 in. Where insulation is desirable, as where the basement is used for living quarters, lightweight aggregate, such as those prepared by calcining or sintering blast-furnace slag, clay, or shale that meet the requirements of ASTM Standard C330 may be used in the concrete. The concrete should have a minimum compressive strength of 2000 psi.

For the forms in which concrete for basement walls is cast, form ties of an

internal-disconnecting type are preferable to twisted-wire ties. Entrance holes for

the form ties should be sealed with mortar after the forms are removed. If twisted wire ties are used, they should be cut a minimum distance of 11?2 in inside the face

of the wall and the holes filled with mortar.

The resistance of the wall to capillary penetration of water in temporary contact

with the wall face may be increased by the use of a water-repellent admixture. The water repellent may also be used in the concrete at and just above grade to reduce

the capillary rise of moisture from the ground into the superstructure wails.

Where it is desirable to make the wall resistant to passage of water vapor from

the outside and to increase its resistance to capillary penetration of water, the exterior wall face may be treated with an impervious coating. The continuity and

the resultant effectiveness in resisting moisture penetration of such a coating is dependent on the smoothness and regularity of the concrete surface and on the skill and technique used in applying the coating to the dry concrete surface. Some bituminous coatings that may be used are listed below in increasing order of their resistance to moisture penetration:

Spray- or brush-applied asphalt emulsions

Spray- or brush-applied bituminous cutbacks

Trowel coatings of bitumen with organic solvent, applied cold

Hot-applied asphalt or coal-tar pitch, preceded by application of a suitable primer Cementitious brush-applied paints and grouts and trowel coatings of a mortar increase moisture resistance of monolithic concrete, especially if such coatings contain

a water repellent. However, in properly drained soil, such coatings may not be justified unless needed to prevent leakage of water through openings in the concrete resulting from segregation of the aggregate and bad workmanship in casting the walls. The trowel coatings may also be used to level irregular wall surfaces in preparation for the application of a bituminous coating. For information on other waterproofing materials, see ‘‘A Guide to the Use of Waterproofing, Dampproofing, Protective a nd Decorative Barrier Systems for Concrete,’’ ACI 515.1R, American Concrete Institute.

3.4.8 Unit-Masonry Basement W alls

Water-resistant basement walls of masonry units should be carefully constructed of durable materials to prevent leakage and damage due to frost and other weathering exposure. Frost action is most severe at the grade line and may result in structural damage and leakage of water. Where wetting followed by sudden severe freezing

may occur, the masonry units should meet the requirements of the following specifications:

Building brick (solid masonry units made from clay or shale), ASTM Standard

C62, Grade SW

Facing brick (solid masonry units made from clay or shale), ASTM Standard

C216, Grade SW

Structural clay load-bearing wall tile, ASTM Standard C34, Grade LBX

Hollow load-bearing concrete masonry units, ASTM Standard C90, Grade N

For such exposure conditions, the mortar should be a Type S mortar (Table 4.4) having a minimum compressive strength of 1800 psi when tested in accordance

with the requirements of ASTM Standard C270. For milder freezing exposures and where the walls may be subjected to some lateral pressure from the earth, the mortar should have a minimum compressive strength of 1000 psi.

Leakage through an expansion joint in a concrete or masonry foundation wall

may be prevented by insertion of a waterstop in the joint. Waterstops should be of

the bellows type, made of l6-oz copper sheet, which should extend a minimum distance of 6 in on either side of the joint. The sheet should be embedded between wythes of masonry units or faced with a 2-in-thick cover of mortar reinforced with welded-wire fabric. The outside face of the expansion joint should be filled flush

with the wall face with a joint sealant, as recommended in ACI 504R.

Rise of moisture, by capillarity, from the ground into the superstructure walls

may be greatly retarded by use of an integral water-repellent admixture in the mortar. The water-repellent mortar may be used in several courses of masonry located at and just above grade.

The use of shotcrete or trowel-applied mortar coatings, 3?4 in or more in thickness,

to the outside faces of both monolithic concrete and unit-masonry walls

greatly increases their resistance to penetration of moisture. Such plaster coatings cover and seal construction joints and other vulnerable joints in the walls against leakage. When applied in a thickness of 2 in or more, they may be reinforced with welded-wire fabric to reduce the incidence of large shrinkage cracks in the coating. However, the cementitious coatings do not protect the walls against leakage if the walls, and subsequently the coatings, are badly cracked as a result of unequal foundation settlement, excessive drying shrinkage, and thermal changes. (‘‘Guide

to Shotcrete,’’ ACI 506, American Concrete Institute.)

Two trowel coats of a mortar containing 1 part portland cement to 3 parts sand

by volume should be applied to the outside faces of basement walls built of hollow masonry units. One trowel coat may suffice on the outside of all-brick and of brickfaced

walls.

The wall surface and the top of the wall footing should be cleansed of dirt and

soil, and the masonry should be thoroughly wetted with water. While still damp,

the surface should be covered with a thin scrubbed-on coating of portland cement tempered to the consistency of thick cream. Before this prepared surface has dried,

a 3?8-in-thick trowel-applied coating of mortar should be placed on the wall and

over the top of the footing; a fillet of mortar may be placed at the juncture of the

wall and footing.

Where a second coat of mortar is to be applied, as on hollow masonry units,

the first coat should be scratched to provide a rough bonding surface. The second

coat should be applied at least 1 day after the first, and the coatings should be

cured and kept damp by wetting for at least 3 days. A water-repellent admixture

in the mortar used for the second or finish coat will reduce the rate of capillary penetration of water through the walls. If a bituminous coating is not to be used,

the mortar coating should be kept damp until the backfill is placed.

Thin, impervious coatings may be applied to the plaster if resistance to penetration

of water vapor is desired. (See ACI 515.1R.) The plaster should be dry and

clean before the impervious coating is applied over the surfaces of the wall and the top of the footing.

3.4.9 Impervious Membranes

These are waterproof barriers providing protection against penetration of water under hydrostatic pressure and water vapor. To resist hydrostatic pressure, a membrane should be made continuous in the walls and floor of a basement. It also should be protected from damage during building operations and should be laid by experienced workers under competent supervision. It usually consists of three or more

alternate layers of hot, mopped-on asphalt or coal-tar pitch and plies of treated glass fabric, or bituminous saturated cotton or woven burlap fabric. The number of moppings

exceeds the number of plies by one.

Alternatives are cold-applied bituminous systems, liquid-applied membranes,

and sheet-applied membranes, similar to those used for roofing. In installation, manufacturers’ recommendations should be carefully followed. See also ACI

515.1R and ‘‘The NRCA Waterproofing Manual,’’ National Roofing Man ufacturers Association.

Bituminous saturated cotton fabric is stronger and is more extensible than bituminous saturated felt but is more expensive and more difficult to lay. At least one

or two of the plies in a membrane should be of saturated cotton fabric to provide strength, ductility, and extensibility to the membrane. Where vibration, temperature changes, and other conditions conducive to displacement and volume changes in

the basement are to be expected, the relative number of fabric plies may be increased. The minimum weight of bituminous saturated felt used in a membrane should

be 13 lb per 100 ft2. The minimum weight of bituminous saturated woven cotton fabric should be 10 oz/yd2.

Although a membrane is held rigidly in place, it is advisable to apply a suitable primer over the surfaces receiving the membrane and to aid in the application of

the first mopped-on coat of hot asphalt or coal-tar pitch.

Materials used in the hot-applied system should meet the requirements of the following current ASTM standards:

Creosote primer for coal-tar pitch—D43

Primer for asphalt—D41

Coal-tar pitch—D450, Type II

Asphalt—D449, Type A

Cotton fabric, bituminous saturated—D173

Woven burlap fabric, bituminous saturated—D1327

Treated glass fabric—D1668

Coal-tar saturated felt—D227

Asphalt saturated organic felt—D226

The number of plies of saturated felt or fabric should be increased with increase

in the hydrostatic head to which the membrane is to be subjected. Five plies is the maximum commonly used in building construction, but 10 or more plies have been recommended for pressure heads of 35 ft or greater. The thickness of the membrane crossing the wall footings at the base of the wall should be no greater than necessary, to keep very small the possible settlement of the wall due to plastic flow in

the membrane materials.

The amount of primer to be used may be about 1 gal per 100 ft2. The amount

of bitumen per mopping should be at least 41?2 gal per 100 ft2. The thickness of

the first and last moppings is usually slightly greater than the thickness of the moppings between the plies.

The surfaces to which the membrane is to be applied should be smooth, dry,

and at a temperature above freezing. Air temperature should be not less than 50_F. The temperature of coal-tar pitch should not exceed 300_F and asphalt, 350_F. absorb the priming coat, and the first mopping of bitumen will be accompanied by bubbling and escape of steam. Should this occur, application of the membrane should be stopped and the bitumen already applied to damp surfaces should be removed.

The membrane should be built up ply by ply, the strips of fabric or felt being

laid immediately after each bed has been hot-mopped. The lap of succeeding plies

or strips over each other depends on the width of the roll and the number of plies.

In any membrane there should be a lap of the top or final ply over the first, initial

ply of at least 2 in. End laps should be staggered at least 24 in, and the laps between succeeding rolls should be at least 12 in.

For floors, the membrane should be placed over a concrete base or subfloor

whose top surface is troweled smooth and which is level with the tops of the wall footings. The membrane should be started at the outside face of one wall and extend over the wall footing, which may be keyed. It should cover the floor and tops of other footings to the outside faces of the other walls, forming a continuous horizontal waterproof barrier. The plies should project from the edges of the floor

membrane and lap into the wall membrane.

The loose ends of felt and fabric must be protected; one method is to fasten

them to a temporary vertical wood form about 2 ft high, placed just outside the

wall face. Immediately after the floor membrane has been laid, its surface should

be protected and covered with a layer of portland-cement concrete, at least 2 in thick.

For walls, the installed membrane should be protected against damage and held

in position by protection board or a facing of brick, tile, or concrete block. A brick facing should have a minim um thickness of 21?2 in. Facings of asphalt plank, asphalt block, or mortar require considerable support from the membrane itself and give protection against abrasion of the membrane from lateral forces only. Protection against downward forces such as may be produced by settlement of the backfill is given only by the self-supporting masonry walls.

The kind of protective facing may have some bearing on the method of constructing the membrane. The membrane may be applied to the exterior face of the

wall after its construction, or it may be applied to the back of the protective facing before the main wall is built. The first of these methods is known as the outside application; the second is known as the inside application.

For the inside application, a protective facing of considerable stiffness against

lateral forces must be built, especially if the wall and its membrane are to be used

as a form for the casting of a main wall of monolithic concrete. The inner face of

the protecting wall must be smooth or else leveled with mortar to provide a suitable base for the membrane. The completed membrane should be covered with a 3?8-inthick

layer of mortar to protect it from damage during construction of the main

wall.

Application of wall membranes should he started at the bottom of one end of

the wall and the strips of fabric or felt laid vertically. Preparation of the surfaces

and laying of the membrane proceed much as they do with floor membranes. The surfaces to which the membrane is attached must be dry and smooth, which may require that the faces of masonry walls be leveled with a thin coat of grout or mortar. The plies of the wall membrane should be lapped into those of the floor membrane.

If the outside method of application is used and the membrane is faced with masonry, the narrow space between the units and the membrane should be filled with mortar as the units are laid. The membrane may be terminated at the grade

line by a return into the superstructure wall facing.

Waterstops in joints in walls and floors containing a bituminous membrane

should be the metal-bellows type. The membrane should be placed on the exposed face of the joint and it may project into the joint, following the general outline of

the bellows.

The protective facing for the membrane should be broken at the expansion joint

and the space between the membrane and the line of the facing filled with a joint sealant, as recommended in ACI 504R.

Details at pipe sleeves running through the membrane must be carefully prepared.

The membrane should be reinforced with additional plies and may be calked

at the sleeve. Steam and hot-water lines should be insulated to prevent damage to

the membrane.

3.4.10 Above-Grade W alls

The rate of moisture penetration through capillaries in above-grade walls is low

and usually of minor importance. However, such walls should not permit leakage

of wind-driven rain through openings larger than those of capillary dimension. Precast-concrete or metal panels are usually made of dense, highly waterresistant materials. However, walls made of these panels are vulnerable to leakage

at the joints. In such construction, edges of the panels may be recessed and the interior of vertical joints filled with grout or other sealant after the panels are aligned.

Calking compound is commonly used as a facing for the joints. Experience has shown that calking compounds often weather badly; their use as a joint facing creates a maintenance problem and does not prevent leakage of wind-driven rain after a few years’ exposure.

The amount of movement to be expected in the vertical joints between panels

is a function of the panel dimensions and the seasonal fluctuation in temperature and, for concrete, the moisture content of the concrete. For panel construction, it

may be more feasible to use an interlocking water-resistant joint. For concrete, the joint may be faced on the weather side with mortar and backed with either a compressible premolded strip or calking. See ACI 504R.

Brick walls 4 in or more in thickness can be made highly water-resistant. The measures that need to be taken to ensure there will be no leakage of wind-driven

rain through brick facings are not extensive and do not require the use of materials

other than those commonly used in masonry walls. The main factors that need to

be controlled are the rate of suction of the brick at the time of laying and filling

of all joints with mortar (Art. 11.7).

In general, the greater the number of brick leaves, or wythes, in a wall, the more water-resistant the wall.

Walls of hollow masonry units are usually highly permeable, and brick-faced

walls backed with hollow masonry units are greatly dependent upon the water resistance of the brick facing to prevent leakage of wind-driven rain. For exterior concrete masonry walls without facings of brick, protection against leakage may

be obtained by facing the walls with a cementitious coating of paint, stucco, or shotcrete.

For wall of rough-textured units, a portland cement–sand grout provides a highly water-resistant coating. The cement may be either white or gray.

Factory-made portland-cement paints containing a minimum of 65%, and preferably 80%, portland cement may also be used as a base coat on concrete masonry. Application of the paint should conform with the requirements of ACI 515.1R. The paints, stuccos, and shotcrete should be applied to dampened surfaces. Shotcrete should conform with the requirements of ACI 506R.

Cavity walls, particularly brick-faced cavity walls, may be made highly resistant

to leakage through the wall facing. However, as usually constructed, facings are highly permeable, and the leakage is trapped in the cavity and diverted to the outside of the wall through conveniently located weep holes. This requires that the inner tier of the cavity be protected against the leakage by adequate flashings, and weep holes should be placed at the bottom of the cavities and over all wall openings. The weep holes may be formed by the use of sash-cord head joints or 3?8-indiameter rubber tubing, withdrawn after the wall is completed.

Flashings should preferably be hot-rolled copper sheet of 10-oz minimum weight. They should be lapped at the ends and sealed either by solder or with bituminous plastic cement. Mortar should not be permitted to drop into the flashings and prevent the weep holes from functioning.

Prevention of Cracking. Shrinkage of concrete masonry because of drying and a drop in temperature may result in cracking of a wall and its cementitious facing. Such cracks readily permit leakage of wind-driven rain. The chief factor reducing incidence of shrinkage cracking is the use of dry block. When laid in the wall, the block should have a low moisture content, preferably one that is in equilibrium

with the driest condition to which the wall will be exposed.

The block should also have a low potential shrinkage. See moisture-content requirements in ASTM C90 and method of test for drying shrinkage of concrete block in ASTM C426.

Formation of large shrinkage cracks may be controlled by use of steel reinforcement in the horizontal joints of the masonry and above and below wall openings.

Where there may be a considerable seasonal fluctuation in temperature and moisture content of the wall, high-yield-strength, deformed-wire joint reinforcement should be placed in at least 50% of all bed joints in the wall.

Use of control joints faced with calking compound has also been recommended

to control shrinkage cracking; however, this practice is marked by frequent failures

to keep the joints sealed against leakage of rain. Steel joint reinforcement strengthens a concrete masonry wall, whereas control joints weaken it, and the calking in

the joints requires considerable maintenance.

shown that leakage of wind-driven rain through masonry walls, particularly those

of brick, ordinarily cannot be stopped by use of an inexpensive surface treatment

or coating that will not alter the appearance of the wall. Such protective devices either have a low service life or fail to stop all leakage.

Both organic and cementitious pigmented coating materials, properly applied as

a continuous coating over the exposed face of the wall, do stop leakage. Many of

the organic pigmented coatings are vapor barriers and are therefore unsuitable for use on the outside, ‘‘cold’’ face of most buildings. If vapor barriers are used on the cold face of the wall, it is advisable to use a better vapor barrier on the warm face

to reduce condensation in the wall and behind the exterior coating.

Coatings for masonry may be divided into four groups, as follows: (1) colorless coating materials; (2) cementitious coatings; (3) pigmented organic coatings; and (4) bituminous coatings.

Colorless Coating Materials. The colorless ‘‘waterproofings’’ are often claimed

to stop leakage of wind-driven rain through permeable masonry walls. Solutions of oils, paraffin wax, sodium silicate, chlorinated rubber, silicone resins, and salts of fatty acids have been applied to highly permeable test walls and have been tested

at the National Institute of Standards and Technology under exposure conditions simulating a wind-driven rain. Most of these solutions contained not more than

10% of solid matter. These treatments reduced the rate of leakage but did not stop

all leakage through the walls. The test data show that colorless coating materials applied to permeable walls of brick or concrete masonry may not provide adequate protection against leakage of wind-driven rain.

Solutions containing oils and waxes tended to seal the pores exposed in the faces

of the mortar joints and masonry units, thereby acting more or less as vapor barriers, but did not seal the larger openings, particularly those in the joints.

Silicone water-repellent solutions greatly reduced leakage through the walls as

long as the treated wall faces remained water-repellent. After an exposure period

of 2 or 3 hr, the rate of leakage gradually increased as the water repellency of the

wall face diminished.

Coatings of the water-repellent, breather type, such as silicone and ‘‘soap’’solutions, may be of value in reducing absorption of moisture into the wall surface. They may be of special benefit in reducing the soiling and disfiguration of stucco facings and light-colored masonry surfaces. They may be applied to precastconcrete panels to reduce volume changes that may otherwise result from changes

in moisture content of the concretes. However, it should be noted that a waterrepellent treatment applied to the surface may cause water, trapped in the masonry,

to evaporate beneath the surface instead of at the surface. If the masonry is not

water-resistant and contains a considerable amount of soluble salts, as evidenced

by efflorescence, application of a water repellent may cause salts to be deposited beneath the surface, thereby causing spalling of the masonry. The water repellents therefore should be applied only to walls having water-resistant joints. Furthermore, application of a colorless material makes the treated face of the masonry waterrepellent

and may prevent the proper bonding of a cementitious coating that could

otherwise be used to stop leakage.

Cementitious Coatings. Coatings of portland-cement paints, grouts, and stuccos

and of pneumatically applied mortars are highly water-resistant. They are preferred above all other types of surface coatings for use as water-resistant base coatings on above-grade concrete masonry. They may also be applied to the exposed faces of brick masonry walls that have not been built to be water-resistant.

The cementitious coatings absorb moisture and are of the breather type, permitting passage of water vapor. Addition of water repellents to these coatings does

not greatly affect their water resistance but does reduce the soiling of the surface

from the absorption of dirt-laden water. If more than one coating is applied, as in

a two-coat paint or stucco facing job, the repellent is preferably added only to the finish coat, thus avoiding the difficulty of bonding a cementitious coating to a waterrepellent

surface.

The technique used in applying the cementitious coatings is highly important.

The backing should be thoroughly dampened. Paints and grouts should be scrubbed into place with stiff fiber brushes and the coatings should be properly cured by wetting. Properly applied, the grouts are highly durable; some grout coatings applied to concrete masonry test walls were found to be as water-resistant after 10

years out-of-doors exposure as when first applied to the walls.

Pigmented Organic Coatings. These include textured coatings, mastic coatings, conventional paints, and aqueous dispersions. The thick-textured and mastic coatings are usually spray-applied but may be applied by trowel. Conventional paints and aqueous dispersions are usually applied by brush or spray. Most of these coatings

are vapor barriers but some textured coatings, conventional paints, and aqueous dispersions are breathers. Except for the aqueous dispersions, all the coatings are recommended for use with a primer.

Applied as a continuous coating, without pinholes, the pigmented organic coatings are highly water-resistant. They are most effective when applied over a smooth backing. When they are applied with paintbrush or spray by conventional methods

to rough-textured walls, it is difficult to level the surface and to obtain a continuous water-resistant coating free from holes. A scrubbed-on cementitious grout used as

a base coat on such walls will prevent leakage through the masonry without the

use of a pigmented organic coating.

The pigmented organic coatings are highly decorative but may not be so waterresistant,

economical, or durable as the cementitious coatings.

Bituminous Coatings. Bituminous cutbacks, emulsions, and plastic cements are

usually vapor barriers and are sometimes applied as ‘‘dampproofers’’ on the inside faces of masonry walls. Plaster is often applied directly over these coatings, the

bond of the plaster to the masonry being only of a mechanical nature. Tests show that bituminous coatings applied to the inside faces of highly permeable masonry walls, not plastered, will readily blister and permit leakage of water through the coating. It is advisable not to depend on such coatings to prevent the leakage of

wind-driven rain unless they are incorporated in the masonry or held in place with

a rigid self-sustaining backing.

Even though the walls are resistant to wind-driven rain, but are treated on their

inner faces with a bituminous coating, water may be condensed on the warm side

of the coating and damage to the plaster may result, whether the walls are furred

or not. However, the bituminous coating may be of benefit as a vapor barrier in furred walls, if no condensation occurs on the warm side.

译文

3.4对水的保护

是否推力反对和成的洪水，大楼的内部的驱动大雨、水暖、风暴潮、或外部渗入泄漏存储模块，水会导致成本高昂的建筑物损。因此，设计师应该保护建筑物和抗水毁其内容。保护措施可分为两类：制作防水。提供了流动表面保护，制作常用的水，由一条河，满溢其银行造成。防水提供保护反渗透进入建筑物的外墙外盘柜的地下水，雨水，和雪融化。大型水体毗邻的建筑物也可能需要由于侵蚀和影响从驱动波风暴破坏的保护。

3.4.1防洪

洪水时发生河高于海拔，称为洪水的阶段，并不是外壳防止造成损害超出其银行。兴建的建筑物平原洪水应该是可以被洪水，被淹没的面积免受洪水与 100 年的平均时间间隔。地图显示在美国的洪水灾害的地区，可从联邦管理员保险、住房和城市发展部，谁负责执行国家洪水保险计划。制作的最低标准载于国家洪水保险规则和条例（联邦登记册卷第 41，207 号，1976 年 10 月 26 日)。

制作的主要目标是保障全面建设和内容从从海港年洪水破坏，更具破坏力发生水灾，减少损失和洪水保险保费较低。制作，不过，会不必要如果建筑物已经不在洪水易发区。在洪水易发区建设除非是可以接受的生命危险和那里的建设可以应避免是经济和社会上合理。

某些站点洪水易发地区拥有一些地面足够高，以避免洪水损坏。如果必须使用此类站点，则建筑物应群集上高的地区。凡等领域不是可用的它可能是可行与建立填土的情况下，堤防受侵蚀对水，提高洪水以上结构水平。最好的是，这种结构不应有的地下室，因为他们会需要水压力对成本高昂的保护。

填充上提升建筑的替代方法提高它对高跷（在列未封闭的空间）。在这种情况下，应保护实用程序和其他服务免于洪水流量的损害。5 在地面踩高跷之间的空间用于停车场汽车，如果是可以接受的水损坏的风险或者如果洪水到达站点之前将被删除。

不能提升洪水舞台上方的建筑物应配有不透水的外墙。应以上洪水的阶段，并应

密封门紧紧地对他们的帧。门和其他开口，也可以保护与洪水的盾牌，如墙。访问也许动产洪水屏蔽，这对于正常的条件可以存储在受保护的建筑物墙体中的空缺看不见，然后定位在墙上时洪水即将打开。

为防止水损坏建筑中泛滥平原，基本服务重要的机械和电气设备应位于洪水级以上。此外，提供一些应急电源辅助电动发电机是可取的。此外，应安装泵泄漏进入大楼的水中弹出。此外，除非建筑物是洪水，紧急的情况下疏散供水应储存在洪水以上坦克和污水系统应该是提供防止回流截止阀。

3.4.2防水

除了保护建筑物免遭水灾，设计师也应采取的措施防止地下水，雨水，雪，或融化的雪水渗透在室内通过外部外壳。水可能泄漏通过裂缝，伸缩缝或其他开口，墙壁和屋顶，或通过附近的裂缝门窗。此外，水会渗透到固体，多孔材料，如砖石。泄漏通常可阻止使用挡风在门窗，防渗止水接头，或嵌的裂缝和其他开口。方法防止渗漏，然而，取决于类型的材料在外部外壳。

术语定义相关的抗水性

渗透性的:性质或状态，允许通过水和水蒸气成，通过，并从孔隙和裂隙，无

破裂或位移.用于本节描述的渗透性的材料，涂料，结构要素和结构，遵循依次

渗透：

透水或漏:裂缝，裂缝，渗漏，或大于毛细管孔隙，这允许流动或渗漏水，是

目前。该材料可能或可能不包含毛细管孔隙。

防水的:毛管孔隙存在，允许水通道和水蒸气，但很少有或没有开口大于毛细

血管允许泄漏大量的水。

防水的:不'wetted '水；因此，不能够发射水毛细管力量。然而，该材料可

允许传输的水压力下可渗透水蒸气。

防水材料:没有开口目前允许泄漏或水通道和水蒸气；材料的防渗水和水蒸气，下压力或不。

这些条款还描述的渗透性表面涂层或处理对水的渗透，和他们指的渗透性的材料，结构成员及结构，不论他们是否已被涂层或处理。

渗透性混凝土和砖石。混凝土中有许多相互关联空隙和各种开孔的尺寸和形状，其中大部分是毛细管尺寸。如果大孔隙和开口数量很少，不直接互相连接，将有很少或没有水的渗透泄漏和混凝土可以说是防水的。

混凝土在压力下与水接触不通常会吸收它。本水是在混凝土的表面张力的液体在湿润

毛细血管。防水混凝土建筑应该是一个适当的固化，密集的，丰富的混凝土耐久，良级配骨料。水含量的混凝土组合应该是低兼容的可操作性和易放置与处理。混凝土抗渗透水可改善，然而，通过成立一个防水剂在制造过程中的混合。（参见：艺术。9.9。）

防水混凝土透水蒸气。如果一个气压梯度目前，水分可以穿透从接触面内面。混凝土不做防水材料（在全词的含义）的使用整体防水。还要注意，不可使混凝土防水剂不透水的渗透水压力下。他们可能，但是，减少水吸收的混凝土。圬工单位水也会吸收最。一些具有高度透水下压力。砂浆中常用的砖石会吸收水太但通常包含几个开口允许泄漏。砌体墙可能泄漏之间的接缝砂浆和单位，然而。除了单墙高渗透单位，泄漏在关节的结果从未能填补他们的迫击炮和穷人之间的圬工单元和砂浆。如混凝土，率毛细管渗透墙是比较小的泄漏率。

毛细管水分渗透通过以上级墙，抵御泄漏风力雨通常是轻微的重要性。这种水

分渗透在通风路基结构也可能是未成年人的重要性，如果水分容易蒸发。然而，长期毛细管渗透入深一些，限于路基内部频繁的结果增加相对湿度，减少蒸发率，而讨厌的潮湿。

3.4.3屋面排水

许多屋顶的失败都是因为水的过度积累。在大多数例，过载，失败的原因是没有预料到在设计这些屋顶，因为设计者预期雨水运行屋顶。但由于缺乏排水，水代替。

平面屋顶雨水，积水原因结构成员偏转。本由此产生的弯曲的屋顶表面允许更多的雨水积聚，和额外的重量的水造成额外的鞠躬和收集甚至更多的水。这个过程可以导致屋顶坍塌。类似的情况也可以发生在山谷的坡屋顶。

避免积水，应向倾斜的屋顶排水管有足够的能力来进行水从屋顶，在与当地水暖码。最小屋面排水坡度应至少1?4在/英尺，但较大的斜坡是可取的。

主要排水系统应辅以二级排水系统在更高的层次，防止积水在屋顶上面那层。本溢流排水应至少一样大的主要排水渠及应排水管连接到独立的主要系统或排水通过护栏。屋顶，其结构应能承受重量所有雨水积聚在屋顶部分或全部的主要排水系统应成为封锁。

3.4.4路基排水结构

路基结构位于地下水位以上的土壤中可在与水接触和湿土的时间无限期后降雨和春季解冻。流域的地表和地下水的，然而，可大大缩短的时间中，墙壁和地板结构是受水，可以防止渗漏通过开口造成的穷人工艺和降低毛细血管渗透水进入结构。如果地下水不能去除引流，结构必须作出防水或防水。

表面的水可以利用分级远离地面分流墙和由携带从远离建筑物屋顶径流。边坡地面应至少在 1?4 / 从 10 呎的最小距离为金融时报》墙壁。从相邻结构的高地上径流应该也改道。适当的地下排水的地面水从地下室墙和地板需要流失的足够大的大小，斜不断，及在有需要时，进行建筑的角落而不会破坏连续性。"排水管应导致雨水沟或不会的低海拔淹没和许可证的水中，备份外流。

图 3.7 排水的底部墙上的基础

排水瓦应具有最小的直径6 的应该放在砂砾或另一种多孔的床上在下面的地下室地板的最少 6。"开缝拼贴之间应该是覆盖着一丝屏幕或建筑防止堵塞下水

道纸用细的材料。上面的拼贴，填充到开挖敷设砾石海拔远高于顶部的基础之上。可能有相当大的水的地方预期沉重的土壤中，砾石填充应执行了近地面表面及应从墙上的扩展距离至少 12 中（图 3.7）。

3.4.5混凝土楼板级

倾斜远离地面。成品的地面应至少6级以上。进一步保护防地面潮气和洪水可能该板从繁重的地表径流与可能获得的地下排水渠坐落在海拔城墙基脚。

所有的有机物质和土壤承载值应删除制备的路基，其中应该有一个统一的价值，防止轴承不均匀沉降的地板板。回填夯实，压实应在深度不超过6层。

在路基排水良好，如在地下水渠用于或不必要的，地板砖住宅应绝缘要么将颗粒填补了路基或通过使用一个在轻骨料混凝土板覆盖与磨损表面的砾石或碎石

混凝土。颗粒填充，如果使用，应有一个最小厚度的5，可能由粗渣，砂砾，或粉碎石，最好是1英寸的最小尺寸。一层3 -，4 -，或空心砖石建筑物，单位

是首选的砾石充填绝缘和提供光滑，水平支承面。

水分从地面可能吸收的楼板。地板覆盖物，如油基漆，油毡，沥青瓦，作为汽层板，可能造成损坏。如果这种地板覆盖物的使用和在一个完整的阻挡上涨的水分从地面是理想，一个

沥青膜或其他防水材料应放在下面板和绝缘混凝土或粒状填料（图3.8）。顶部

的在轻骨料混凝土，如果使用，应抹子或刷平滑水平的膜表面。顶部的颗粒填充应覆盖灌浆涂料，同样完成。（泥浆大衣，1?2到1厚，可能包括一个1 : 3或4混合体积的波特兰水泥和沙子。3?8 -或1?2最大规模的粗集料可能被添加到泥浆后，如果需要的话。）顶部表面的绝缘混凝土或砂浆涂层硬化和干燥，它应擦与热沥青或煤焦油沥青覆盖冷却之前与叠层15-lb沥青油毡。在第一层的感觉应擦与热沥青和二层毛毡擦上了其顶部表面。应注意避免穿刺膜，这最好是覆盖着一层砂浆，完成后立即。

如果合理布置和损害的保护膜，可以考虑是一个防水层。那里是没有可能的危险，水到地板下面，单层55-lb表面沥青屋面卷材防水或等效膜可用于地板下。板之间的关节应研磨和密封与沥青玛蹄脂。应十分注意防止穿刺的屋面层混凝土浇筑时操作。所以安装时，沥青屋面卷材提供了一个低成本和适当的阻挡运动过量的水分通过毛细作用和形式的蒸汽。在领域

全年气候温暖，绝缘可以省略。（' '指南使用防水，防潮，保护和装饰屏障系统混凝土，' '机场515.1r，美国混凝土学会。）

图3.8隔热混凝土板与地面防潮膜。

3.4.6地下室地板

在一个地下室是用在排水良好的土壤住所或存储东西可以被破坏的水分，地板应包绝缘和应最好包含防水膜中所描述的艺术。图一般设计和施工的地下室地板相似，地板地面上的。

如果水分通过从地面到地下室是无关紧要的或可令人满意的控制空调或通风，防水膜不需要使用。混凝土板应该有一个最小厚度4、不需要被强化，但应该放在一个颗粒填充或其他

绝缘放置在一个精心准备的路基。混凝土板中的应有一个最低抗压强度为2000防扩散和可能包含一个完整的拒水。

一个地下室的地板下面的表将水压上压力。地面应成为重足以抵消隆起。

一个适当的密封胶在关节之间的地下室的墙壁和地板土壤的防止泄漏到地下室的水，可能偶尔积累下板。空间为可提供联合使用斜壁板条，被拆除后的混凝土硬化。后板的适当固化，它与墙面应在干燥条件是可行前接头填充确保良好的债券的填料和减少影响板收缩对渗透率的接头。

3.4.7单片混凝土地下室墙

这些应该有 6 中的最小的厚度。其中保温材料是可取的作为地下室用于居住地、轻骨料，如那些煅烧或矿渣、粘土或满足的页岩烧结法制备在混凝土中可使用的 ASTM 标准 c330 钱箱的要求。混凝土应具有最小的压缩强度的 2000 磅/平方英寸。

因为地下室混凝土墙转换的形式形成的关系内部断开连接类型是绞丝关系更为可取。入口孔窗体中删除后，应用砂浆密封形式的联系。如果使用联系，他们应削减内部脸在 11?2 的最小的距离在墙上和孔填充砂浆。

电阻的毛细血管渗透的临时接触水墙与墙可作防水剂的使用增加的脸。"拒水可能也用于混凝土只以上等级中减少水分从地面到上层建筑的毛细管崛起。

哪里适宜作出的水汽通道耐墙在外面，并增加其电阻毛细血管渗透的水，外墙的脸可能治疗不透水的涂层。连续性和在这种涂料的抗水分渗透结果的有效性是依赖于平整度和规律的混凝土表面和技巧和中在干的混凝土表面涂层的应用技术。一些下面列出了可使用的沥青涂层中增加的顺序排列它们抗透湿性：

喷涂或刷适用沥青乳液

喷涂或刷适用沥青削减

镘涂层沥青与有机溶剂，采用冷

热铺沥青或煤焦油沥青，先申请一个合适的引物

胶凝应用刷涂料和薄浆和抹灰砂浆的涂料增加耐湿性能的单片混凝土，尤其是如果这种涂料包含拒水。然而，在正常排水的土壤，这种涂料可能不是除非需要以防止的开口在混凝土渗漏的理由造成的隔离的聚合和坏的铸造工艺墙壁。抹灰涂料还可用于在级别的不规则墙体表面沥青涂层的应用的准备。有关其他信息防水材料，请参阅使用的防水、防潮，指南混凝土、保护和装饰的屏障系统 ACI 515.1R，美国混凝土研究所。

3.4.8 unit-masonry地下室墙

耐水地下室墙砌体单位的应该仔细地建造的耐用的材料，以防止泄漏和霜和其它风化因损坏曝光。霜行动在等级行最为严重，并可能导致在结构损伤和泄漏的水。在润湿跟随突然严重冻结可能会发生，砌体单位应符合以下规范：

建筑砖（实心砌块粘土或页岩制），标准

土木工程专业英语翻译

a common way to construct steel truss and prestressed concrete cantilever spans is to counterbalance each cantilever arm with another cantilever arm projecting the opposite direction,forming a balanced cantilever. they attach to a solid foundation ,the counterbalancing arms are called anchor arms /thus,in a bridge built on two foundation piers,there are four cantilever arms ,two which span the obstacle,and two anchor arms which extend away from the obstacle,because of the need for more strength at the balanced cantilever's supports ,the bridge superstructure often takes the form of towers above the foundation piers .the commodore barry bridge is an example of this type of cantilever bridge 一种常见的方法构造钢桁架和预应力混凝土悬臂跨度是每一个悬臂抗衡预测相反的方向臂悬臂，形成一个平衡的悬臂。他们重视了坚实的基础，制约武器被称为锚武器/因此，在两个基础上建一座桥桥墩，有四个悬臂式武器，这两者之间跨越的障碍，和两个锚武器哪个延长距离的障碍，因为为更多的在平衡悬臂的支持力量的需要，桥梁上部结构往往表现为塔墩基础之上形成的准将巴里大桥是这种类型的例子悬臂桥 steel truss cantilever support loads by tension of the upper members and compression of the lower ones .commonly ,the structure distributes teh tension via teh anchor arms to the outermost supports ,while the compression is carried to the foundation beneath teh central towers .many truss cantilever bridges use pinned joints and are therefore statically determinate with no members carrying mixed loads 钢桁架悬臂由上层成员和下层的紧张压缩支持负载。通常，结构分布通过锚武器的最外层的支持紧张，而压缩抬到下方的中央塔的基础。桁架悬臂许多桥梁使用固定的关节，是静定，没有携带混合负载的成员，因此 prestressed concrete balanced cantilever bridges are often built using segmental construction .some steel arch bridges are built using pure cantilever spans from each sides,with neither falsework below nor temporary supporting towers and cables above ,these are then joined with a pin,usually after forcing the union point apart ,and when jacks are removed and the bridge decking is added the bridge becomes a truss arch bridge .such unsupported construction is only possible where appropriate rock is available to support the tension in teh upper chord of the span during construction ,usually limiting this method to the spanning of narrow canyons 预应力混凝土平衡悬臂桥梁往往建立使用段施工。一些钢拱桥是使用各方面的纯悬臂跨度既无假工作下面也临时支撑塔和电缆上面，这些都是再加入了一根针，通常在迫使工会点外，当插孔删除，并添加桥梁甲板桥成为桁架拱桥，这种不支持的建设，才可能在适当情况下的岩石可用于支持在施工期间的跨度弦上的张力，通常限制这狭隘的峡谷跨越方法 an arch bridge is a bridge with abutments at each end shaped as a curved arch .arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side .a viaduct may be made from a series of arches ,although other more economical structures are typically used today 在拱桥桥台的桥梁，是一个在一个弧形拱状，每年年底。拱桥通过转移到由部分在两边的桥台水平推

土木工程专业英语课文原文及对照翻译

土木工程专业英语课文原 文及对照翻译 Newly compiled on November 23, 2020

Civil Engineering Civil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities. 土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities. 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 The word civil derives from the Latin for citizen. In 1782, Englishman John Smeaton used the term to differentiate his nonmilitary engineering work from that of the military engineers who predominated at the time. Since then, the term civil engineering has often been used to refer to engineers who build public facilities, although the field is much broader 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 Scope. Because it is so broad, civil engineering is subdivided into a number of technical specialties. Depending on the type of project, the skills of many kinds of civil engineer specialists may be needed. When a project begins, the site is surveyed and mapped by civil engineers who locate utility placement—water, sewer, and power lines. Geotechnical specialists perform soil experiments to determine if the earth can bear the weight of the project. Environmental specialists study the project’s impact on the local area: the potential for air and

土木工程专业英语原文及翻译

土木工程专业英语原文 及翻译 文档编制序号：[KKIDT-LLE0828-LLETD298-POI08]

08 级土木(1) 班课程考试试卷 考试科目专业英语 考试时间 学生姓名 所在院系土木学院 任课教师 徐州工程学院印制 Stability of Slopes Introduction Translational slips tend to occur where the adjacent stratum is at a relatively shallow depth below the surface of the slope:the failure surface tends to be plane and roughly parallel to the slips usually occur where the adjacent stratum is at greater depth，the failure surface consisting of curved and plane sections． In practice, limiting equilibrium methods are used in the analysis of slope stability. It is considered that failure is on the point of occurring along an assumed or a known failure surface．The shear strength required to maintain a condition of limiting equilibrium is compared with the available shear strength of the soil，giving the average factor of safety along the failure surface．The problem is considered in two dimensions，conditions of plane strain being assumed．It has been shown that a two-dimensional analysis gives a conservative result for a failure on a three-dimensional(dish-shaped) surface． Analysis for the Case of φu =0 This analysis, in terms of total stress，covers the case of a fully saturated clay under undrained conditions, . For the condition immediately after construction．Only moment equilibrium is considered in the analysis．In section, the potential failure surface is assumed to be a circular arc. A trial failure surface(centre O，radius r and length L a where F is the factor of safety with respect to shear strength．Equating moments about O：

土木工程英语翻译1doc

Chapter 10 Construction Management 建设管理部门 10.1 the procurement and implementation of structural steel for buidings begins with the owner`s decision to use steel as the primary structural system for the building 采购和实现的钢结构的建筑开始与业主的决定使用钢作为主要结构系 统的构建 this decision is generally made early in the design process in conjunction with the architect and structural engineer for the project 10.1 这个决定通常是在设计过程中尽早做出会同建筑师和结构工程师的项目 the construction manager or design-build firm advises the owner on material availability 设计、建设施工经理或公司建议业主在材料的可用性 costs, suitability 成本、适用性 and scheduling aspects of the structural frame types和调度方面的结构性框架类型 in many cases 在许多情况下 the construction manager or design-build firm consults with steel fabricators for preliminary pricing设计、建设施工经理或公司担任钢铁制造商为初步定价scheduling, and layout information that is used in deciding which structural system to utilize 调度和布局信息,用于决定哪些结构系统利用 Structural Design 结构设计

土木中英翻译

2.4 开启功能修复 解放桥中跨为开启跨，开启系统为施尔泽尔（Scherzer）式。这一系统通过电动机的动力输送，由齿轮组、动轮、齿条、弧形梁、平衡重密切的配合运动，使得末端齿轮轴的水平移动转化成扇形齿在固定齿梁上的滚动，这一随着开启角度而变化的转动轴，使桥梁在开启过程中，整个开启跨结构围绕转动轴处于受力的平衡状态，使桥梁有控制地徐徐向后仰起完成开启动作。桥梁开启后，两墩之间有42.7m的自由航道。 2.4 Repairing of the movable function The middle span of Liberation Bridge is a movable span whose movable system is Scherzer’s pattern. The opening system is driven by an electric motor. With the team motion of gear set, driving wheel, rack, curved beam and balance weight, horizontal motion of the gear shaft can be converted to be the roll of gear sector on fixed gear whose position varies with opening angle. Bridge structure is on the state of equilibrium with respect to the rotation axis when opening, which make it possible to open the bridge deck gradually in a controllable way. The width of free waterway is about 42.7m after bridge deck is opened. 解放桥开启系统严格按照原开启方式恢复，主要通过三步工作来实现。 1.通过实地考察、勘查与了解，明确解放桥的开启系统原理，完成开启系统的设计工作。 The opening system is repaired strictly according to the former opening pattern, and the repairing procedure can be divided into three steps as follows: 1. After field investigation and exploration, design the opening system with clearly comprehending the principle of opening system of Liberation Bridge. 2.安装调试 (1).车间内初安装调试 在车间内首先对每个传动部件进行初安装，调整好齿轮、支承件的位置与间隙，并在各个支承部件处加润滑脂，保证部件转动灵活；在车间内搭设辅助初调试平台，将所有上桥传动部件放在车间内的辅助初调试平台上，单侧活动跨的整体传动系统联接安装初调试，调整好各对齿轮间的位置与间隙，并在各个支承部件处加润滑脂，使得系统转动灵活，检查全部零部件并确认无遗漏情况。 2 Installation debugging (1) Initially installation debugging in workshop Every transmission part should be initially installed firstly in workshop. In this stage, the position of each gear and strutting piece should be adjusted and lubricating oil should be applied to each strutting piece to make sure their free rotation. Then all the transmission parts should be placed on the auxiliary initial debugging platform in

土木工程专业英语翻译(武汉理工大学出版社段兵廷主编)完整版

第一课土木工程学 土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 领域。因为包含范围太广，土木工程学又被细分为大量的技术专业。不同类型的工程需要多种不同土木工程专业技术。一个项目开始的时候，土木工程师要对场地进行测绘，定位有用的布置，如地下水水位，下水道，和电力线。岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。环境工程专家研究工程对当地的影响，包括对空气和地下水的可能污染，对当地动植物生活的影响，以及如何让工程设计满足政府针对环境保护的需要。交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。同时，结构工程专家利用初步数据对工程作详细规划，设计和说明。从项目开始到结束，对这些土木工程专家的工作进行监督和调配的则是施工管理专家。根据其他专家所提供的信息，施工管理专家计算材料和人工的数量和花费，所有工作的进度表，订购工作所需要的材料和设备，雇佣承包商和分包商，还要做些额外的监督工作以确保工程能按时按质完成。 贯穿任何给定项目，土木工程师都需要大量使用计算机。计算机用于设计工程中使用的多数元件（即计算机辅助设计，或者CAD）并对其进行管理。计算机成为了现代土木工程师的必备品，因为它使得工程师能有效地掌控所需的大量数据从而确定建造一项工程的最佳方法。 结构工程学。在这一专业领域，土木工程师规划设计各种类型的结构，包括桥梁，大坝，发电厂，设备支撑，海面上的特殊结构，美国太空计划，发射塔，庞大的天文和无线电望远镜，以及许多其他种类的项目。结构工程师应用计算机确定一个结构必须承受的力：自重，风荷载和飓风荷载，建筑材料温度变化引起的胀缩，以及地震荷载。他

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外文文献及译文 文献、资料题目：PROTECTION AGAINST HAZARDS 院（部）：建筑工程学院 专业：土木工程 班级：土木081 姓名：孙继佳 学号：200811003192 指导教师：樊江 翻译日期：2012.5.4

3.1 PROTECTION AGAINST WA TER Whether thrust against and into a building by a flood, driven into the interior by a heavy rain, leaking from plumbing, storm surge, or seeping through the exterior enclosure, water can cause costly damage to a building. Consequently, designers should protect buildings and their contents against water damage. Protective measures may be divided into two classes: floodproofing and waterproofing.Floodproofing provides protection against flowing surface water, commonly caused by a river overflowing its banks. Waterproofing provides protection against penetration through the exterior enclosure of buildings of groundwater, rainwater,and melting snow. Buildings adjacent to large water bodies may also require protection from undermining due to erosion and impact from storm driven waves. 3.4.1Floodproo?ng A ?ood occurs when a river rises above an elevation,called ?ood stage,and is not Prevented by enclosures from causing damage beyond its banks.Buildings con- Structed in a ?ood plain,an area that can be inundated by a ?ood,should be Protected against a ?ood with a mean recurrence interval of 100 years.Maps Showing ?ood-hazard areas in the United States can be obtained from the Federal InsuranceAdministrator,DepartmentofHousingandUrbanDevelopment,who Administers the National Flood Insurance Program.Minimum criteria for?ood- proo?ng are given in National Flood Insurance Rules and Regulations(Federal Register, vol.41,no.207,Oct.26,1976). Major objectives of ?oodproo?ng are to protect fully building and contents from Damage from a l00-year ?ood,reduce losses from more devastating ?oods,and Lower ?ood insurance premiums.Floodproo?ng,however,would be unnecessary if Buildings were not constructed in ?ood prone areas.Building in ?ood prone areas Should be avoided unless the risk to life is acceptable and construction there can Be economically and socially justi?ed. Some sites in flood prone areas possess some ground high enough to avoid flood damage. If such sites must be used, buildings should be clustered on the high areas. Where such areas are not available, it may be feasible to build up an earth fill, with embankments protected against erosion by water, to raise structures above flood levels. Preferably, such structures should not have basements, because they would require costly protection against water pressure. An alternative to elevating a building on fill is raising it on stilts (columns in an unenclosed space). In that case, utilities and other services should be protected against damage from flood flows. The space at ground level between the stilts may be used for parking automobiles, if the risk of water damage to them is acceptable or if they will be removed before flood waters reach the site. Buildings that cannot be elevated above flood stage should be furnished with an impervious exterior. Windows should be above flood stage, and doors should seal tightly against their frames. Doors and other openings may also be protected with a flood shield, such as a wall. Openings in the wall for access to the building may be protected with a movable flood shield, which for normal conditions can be stored

土木工程中英文翻译

Structural Systems to resist lateral loads Commonly Used structural Systems With loads measured in tens of thousands kips, there is little room in the design of high-rise buildings for excessively complex thoughts. Indeed, the better high-rise buildings carry the universal traits of simplicity of thought and clarity of expression. It does not follow that there is no room for grand thoughts. Indeed, it is with such grand thoughts that the new family of high-rise buildings has evolved. Perhaps more important, the new concepts of but a few years ago have become commonplace in today’ s technology. Omitting some concepts that are related strictly to the materials of construction, the most commonly used structural systems used in high-rise buildings can be categorized as follows: 1.Moment-resisting frames. 2.Braced frames, including eccentrically braced frames. 3.Shear walls, including steel plate shear walls. 4.Tube-in-tube structures. 5.Tube-in-tube structures. 6.Core-interactive structures. 7.Cellular or bundled-tube systems. Particularly with the recent trend toward more complex forms, but in response also to the need for increased stiffness to resist the forces from wind and earthquake, most high-rise buildings have structural systems built up of combinations of frames, braced bents, shear walls, and related systems. Further, for the taller buildings, the majorities are composed of interactive elements in three-dimensional arrays. The method of combining these elements is the very essence of the design process for high-rise buildings. These combinations need evolve in response to environmental, functional, and cost considerations so as to provide efficient structures that provoke the architectural development to new heights. This is not to say that imaginative structural design can create great architecture. To the contrary, many examples of fine architecture have been created with only moderate support from the structural engineer, while only fine structure, not great architecture, can be developed without the genius and the leadership of a talented architect. In any event, the best of both is

土木工程中英文翻译

from：journal of Constructional Steel Research.V olume 59,Number 1,January 2003 Cyclic behavior of steel moment frame connections under varying axial load and lateral displacements Abstract: This paper discusses the cyclic behavior of four steel moment connections tested under variable axial load and lateral displacements. The beam specim- ens consisted of a reduced beam section, wing plates and longitudinal stiffeners. The test specimens were subjected to varying axial forces and lateral displace- ments to simulate the effects on beams in a Coupled-Girder Moment-Resisting Framing system under lateral loading. The test results showed that the specim- ens responded in a ductile manner since the plastic rotations exceeded 0.03 rad without significant drop in the lateral capacity. The presence of the longitudin- al stiffener assisted in transferring the axial forces and delayed the formation of web local buckling. 1. Introduction Aimed at evaluating the structural performance of reduced-beam section(RBS) connections under alternated axial loading and lateral displacement, four full-scale specimens were tested. These tests were intended to assess the performance of the moment connection design for the Moscone Center Exp- ansion under the Design Basis Earthquake (DBE) and the Maximum Considered Earthquake (MCE). Previous research conducted on RBS moment connections [1,2] showed that connections with RBS profiles can achieve rotations in excess of 0.03 rad. However, doubts have been cast on the quality of the seismic performance of these connections under combined axial and lateral loading. The Moscone Center Expansion is a three-story, 71,814 m2 (773,000 ft2) structure with steel moment frames as its primary lateral force-resisting system. A three dimensional perspective illustration is shown in Fig. 1. The overall height of the building, at the highest point of the exhibition roof, is approxima- tely 35.36 m (116ft) above ground level. The ceiling height at the exhibition hall is 8.23 m (27 ft) , and the typical floor-to-floor height in the building is 11.43 m (37.5 ft). The building was designed as type I according to the requi- rements of the 1997 Uniform Building Code. The framing system consists of four moment frames in the East–West direct- ion, one on either side of the stair towers, and four frames in the North–South

土木工程专业英语(苏小卒版)翻译.

第一单元 Fundamentally, engineering is an end-product-oriented discipline that is innovative, cost-conscious and mindful of human factors. It is concerned with the creation of new entities, devices or methods of solution: a new process, a new material, an improved power source, a more efficient arrangement of tasks to accomplish a desired goal or a new structure. Engineering is also more often than not concerned with obtaining economical solutions. And, finally, human safety is always a key consideration. 从根本上，工程是一个以最终产品为导向的行业，它具有创新、成本意识，同时也注意到人为因素。它与创建新的实体、设备或解决方案有关：新工艺、新材料、一个改进的动力来源、任务的一项更有效地安排，用以完成所需的目标或创建一个新的结构。工程是也不仅仅关心获得经济的解决方案。最终，人类安全才是一个最重要的考虑因素。 Engineering is concerned with the use of abstract scientific ways of thinking and of defining real world problems. The use of idealizations and development of procedures for establishing bounds within which behavior can be ascertained are part of the process. 工程关心的是，使用抽象的科学方法思考和定义现实世界的问题。理想化的使用和发展建立可以确定行为的边界的程序，是过程的一部分。 Many problems, by their very nature, can’t be fully described—even after the fact, much less at the outset. Yet acceptable engineering solutions to these problems must be found which satisfy the defined needs. Engineering, then, frequently concerns the determination of possible solutions within a context of limited data. Intuition or judgment is a key factor in establishing possible alternative strategies, processes, or solutions. And this, too, is all a part of engineering. 很多的问题，就其本身的性质而言，不能完全被描述——即使这一事实，在其开始之前。然而还必须找到对于这些问题可接受的工程解决方案，来满足预定的需求。直觉或判断是建立可能的替代策略、流程或解决方案的关键因素。。而这也是工程的一部分。 Civil engineering is one of the most diverse branches of engineering. The civil engineer plans, designs, constructs, and maintains a large variety of structures and facilities for public, commercial and industrial use. These structures include residential, office, and factory buildings; highways, railways, airports, tunnels, bridges, harbors, channels, and pipelines. They also include many other facilities that are a part of the transportation systems of most countries, as well as sewage and waste disposal systems that add to our convenience and safeguard our health. 土木工程是工程的最多样化的分支机构之一。土木工程师计划、设计、施工，和维护大量的结构和公共、商业和工业使用的设施。这些结构包括住宅，办公室和工厂大厦；公路、铁路、机场、隧道、桥梁、港口、渠道和管道。在其他大多数的国家它们还包括运输系统许多其他设施，以及将为我们的生活带来便利的和维护我们的健康污水及废物处理系统。 The term “civil engineer” did not come into use until about 1750, when John