土木工程外文翻译
本科毕业设计（论文）外文翻译译文
学生姓名：
院（系）：
专业班级：
指导教师：
完成日期：
钢筋混凝土填充框架结构对拆除两个相邻的柱的响应
作者：Mehrdad Sasani 美国波士顿东北大学，斯奈尔400设计中心MA02115
收稿日期：2007年7月27日，修整后收稿日期2007年12月26日，录用日期2008年1月24日，网上上传日期2008年3月19日。
摘要：
本文是评价圣地亚哥旅馆对同时拆除两根相邻的外柱的响应问题，圣地亚哥旅馆是个6层钢筋混凝土填充框架结构。结构的分析模型应用了有限元法和以此为基础的分析模型来计算结构的整体和局部变形。分析结果跟实验结果非常吻合。当测量的竖向位移增加到为四分之一英寸（即6.4mm）的时候，结构就发生连续倒塌。通过实验分析方法评价和讨论随着柱的移除而产生的变形沿着结构高度上的发展和荷载动态重分配。讨论了轴向和弯曲的变形传播的不同。结构横向和纵向的三维桁架在填充墙的参与下被认为是荷载重分配的主要构件。讨论了两种潜在的脆性破坏模型（没有拉力加强的梁的脆断和有加筋肋的梁的挤出）。分析评价了结构对额外的重力和无填充墙时的响应。
Elsevier有限责任公司对此文保留所有权利。
关键词：
连续倒塌；荷载重分配；对荷载抵抗能力；动态响应；非线性分析；脆性破坏。
1. 介绍：
作为减小由于结构的局部损坏而造成大量伤亡的可能性措施的一部分，美国总务管理局【1】和国防部【2】出台了一系列制度来评价结构对连续倒塌的抵抗力。【3】定义连续倒塌为，由原始单元的局部破坏在单元间的扩展最终造成结构的整体或不成比例的大部破坏。
通过Ellingwood 和Leyendecker【4】建议的方法，ASCE/SEI 7定义了两种一般模型来减小结构设计时连续倒塌效应产生的损害，它们分为直接和间接的设计方法。一般建筑规范和标准用增加结构的整体性的间接设计方法。间接设计法也应用于美国国防部的降低连续倒塌设计和未归档设备标准中。尽管间接设计法可以降低连续破坏的风险【6，7】，对基于此法设计的结构破坏后的表现的判断是不容易实现的。
有一种基于直接设计的方法通过研究瞬间消除受载构件，比如柱子，对结构的影响来评价结构的连续倒塌。美国防部和国家事务管理局的规章是要求去除一个受荷构件，考虑其影响。这样的规范目的是评价结构的整体性和结构的一个单元出现严重的毁坏时的分荷能力。这种方法是研究结构受连续倒塌的影响的程度，但是事实上初始结构损伤的影响不止局限于某一根柱子。
在本论文中，应用通过实验证实的分析结果，评价圣地亚哥旅馆抵抗连续破坏的
能力，实验中瞬间移除两个相邻的柱子，其中一个柱是拐角柱。为了爆除这两个柱子，将炸药放在预先在柱子上钻的孔里面。柱子然后再用几层保护材料包裹好，以避免爆炸时的冲击波和碎片影响结构的其他部分。
2. 建筑的特性
圣地亚哥旅馆建造于1914年，在1924年又向南扩展了一部分，此部分包括两个分离的结构。图.1是从南边看旅馆的样子。注意这张照片，旅馆的第一和第三层被用黑色的布蒙了起来。这个六层的旅馆是无延性的钢筋混凝土框架结构，其中还有由空心砖构成的填充外墙。扩展部分的填充墙有两层共203mm厚。第一层的楼高为6.0m，其他楼盖高为3.2m，顶楼高度为5.13m。图.2为其中一个扩展部分的第二层。图.3为对本建筑的实施计划，即瞬间爆除一层相邻的柱A2和A3，以评价其影响。
左图：图.1 圣地亚哥旅馆的南端视角，本论文研究其中心结构
右图：图.2 扩展结构的第二层（南端视角）
下图：图.3 拟对旅馆南扩展部分实施的柱的移除计划，第一
层要被移除的柱用叉号标出
如图.3所示楼盖系统纵向（南北向）有一个托梁。根据两个混凝土构件受压的实验结果，对一个标准的混凝土柱，受压承载力为31MPa。混凝土的弹性模量大概为26300MPa左右。同样，通过横截面12.7mm的钢筋受拉实验，其屈服和极限抗拉强度分别为427和600MPa。钢筋的极限变形为0.17。钢筋的弹性模量近似为200000MPa。
这个建筑按计划将被爆破摧毁。作为摧毁的一个步骤，第一层和第三层的填充墙被移除。移除时上面没有活荷载。所有的非结构部件包括隔墙、管道设备、家具都被事先搬走了，只有梁、柱、楼板梁和在边梁上的填充墙被留下。
3. 传感器布置
混凝土和钢筋的应变传感器是用来测量梁和柱的应变变化的。线性电位计用来测量整体和局部变形。混凝土应变测量仪常900mm，最大应变为±0.02.钢筋应变测量仪应变极限为±0.2。应变测量仪可以带到几百千赫兹。电位计用来测量建筑中梁沿一端的转动和整体位移，这些以后将讲到。电位计的分辨率为0.01mm，最大速度为1.0m/s，实验中最大记录速度为0.35m/s。
4. 有限元模型
通过有限单元法，在软件SAP2000【8】中生成一个建筑模型。梁和柱都被抽象成Bernoulli单元。T和L型梁的翼缘计算宽度为四倍的较厚板的厚度【5】。塑性铰可以发生在任何钢筋可能发生屈服的地方，包括单元的端点、加筋肋分离点和弯矩的屈服点。在分析中，塑性铰的范围是构件高度的一半。现行版本的SAP2000不能计算出单元斜裂缝的构成。为了得出正确的构件挠曲刚度，反复做以下步骤：首先假设建筑的所有单元都是没有裂缝的；然后，需要弯矩同构件的出现裂缝的弯矩相比较。分别降低板厚和梁的惯性矩35%，使需求弯矩大于裂缝出现弯矩。梁外部出现裂缝的正负弯矩分别为58.2knM和37.9knM。需要注意的是柱子没有裂缝出现。再后，再按以上方法重新分析建筑和弯矩简图。重复这些步骤直到所有的裂缝区域被鉴定和用模型表示出来。除了两端区域建筑结构里的梁上部不配筋（图.4）。例如，梁A1-A2在距A1点305mm以后，其上部不配筋（如图.4和5）。为了确定出可能丧失挠曲强度的截面位置，将裂纹铰布置在上部没有配筋的可能的弯曲破坏点上。塑性铰的挠曲强度设为于Mcr相等，当所受的弯矩达到Mcr时，该截面即发生破坏。
图.4 二层的梁A3-B3和梁A1-A2详细配筋情况
楼盖系统有沿纵向（南北向）的次梁。图.6所示为一典型的楼盖的横截面。为了计算出次梁和板的可能的非线性响应，用梁单元为楼盖建立模型。次梁按T型梁计算，翼缘的计算宽度为各自板厚的四倍【5】。选取轴2和轴3的纵梁和其之间的一个宽20英寸的梁间的格栅为板的计算模型。为了给出板沿横向的计算模型，同样用一个宽20英寸于横梁平行的梁。在方形的板中其剪力流和梁单元的中的不一样。所以其扭转刚
度取为整个截面刚度的一半【9】。
图.5 梁的上部配筋弯曲位置（于梁A1-A2相似，在邻近建筑靠近柱A1的地方）
图.6 典型的楼盖的次梁系统
图.7 实验和分析的第二层柱A3的竖向位移
建筑的2、4、5、6层有填充墙，并在门窗等开口位置有过梁，如前面提到的第1、三层的填充墙，在爆除前已经拆掉。填充墙是用良好的空隙砖砌成的，空心砖的净空是其总大小的一半。填充墙的平面效应增强了建筑的刚度和强度，并且影响建筑的对荷载反应即变形。如果忽略墙的影响将得不到准确的建筑的刚度和强度。
在SAP2000中考虑了两种填充墙的形式：一种是用平面框架模型（模型A），另一种是FEMA365【10】中建议的受压杆件模型（模型B）。
4.1模型A是平面框架模型，但是，现行版本的SAP2000只能计算线性框架模型，不能计算裂缝的发展情况。填充墙的抗拉强度大概为26psi，弹性模量为644ksi【10】。由于裂缝的发展对填充墙的刚度影响很大，重复以下步骤来计算裂缝的形成：（1）假设填充墙是线性的而且没有开裂，运行非线性历史分析。由于梁中的塑性铰的存在，梁中弯矩大于裂缝出现弯矩时候，对截面惯性矩有一个折减。
（2）判定填充墙出现的依据是看其应力于墙的抗拉强度大小关系。
（3）节点在拉应力大于抗拉强度的地方分离。
重复上面的步骤直到裂缝区域被确定。
4.2.模型B（受压杆件模型）
如FEMA356【10】所述用受压杆件来代替填充墙，杆件的方向根据移除柱后的结构变形形式和开口位置确定。
4.3.柱的移除
按以下步骤模拟柱的移除。
结构是在只受永久荷载下分析的，内力在柱端测定，将随着柱的移除而卸荷。
模型的建立是在移除第一层的柱A2、A3的情况下进行的。结构同样是在永久荷载下进行静态分析的。在此情况下，测得的柱端内力被当成永久外部荷载施加在结构上。注意此分析结果跟第一步的分析是等价的。
第二步中大小相等方向相反的柱端力，被瞬间施加在原柱的位置上，然后进行动态分析。
4.4.实验和分析结果的比较
结构计算最大竖向位移在第二层的柱A3上，图7所示为按模型A的实验和分析的梁A3竖向位移的比较。实验数据是用三个粘在A3两端的传感器记录的。实验和分析得到的最大位移分别是6.1mm和6.4mm，相差尽为4%。实验和分析的位移产生所用时间分别为0.069S和0.066S。分析结果显示永久位移为5.3mm，比实验结果小14%，实验结果为6.1mm。
图.8.第二层的柱A3在模型A和B下分别沿时间的竖向位移
图.8.比较了第二层的柱A3分别在模型A和B下分析的沿时间的竖向位移。由图中可以看出，按受压杆件模型（模型B）得出的最大竖向位移为11.4mm,比用模型A得出的结果高出约80%。在图.7.可以看出按模型A得出的结果与实验结果是想接近的，B 模型得出的结构变形过高。如果最大竖向位移偏大的话，填充墙开裂情况会更加严重，更偏向于受压杆件形成，模型A和模型B得出结果差异将减小。
图.9.比较了用模型A时第二层的柱A2的分析和实验的位移值。同样，第一次达到最大位移值的实验和分析值非常接近，分析的永久位移值比实验的位移值略微低些。图.10.所示为根据模型A得出的最大竖向位移的结构变形放大200倍后的情况。
图.9.第二层的柱A2竖向位移实验和分析结果比较
图.10.按模型A，FEM分析的结构变形形式（第二层的实验得出变形形式也给出）通过实测得的变形形式在图中也用实线标出了。在二层的梁A1-A2、A3-B3的上下端部应力重分配复杂的地方共用了14个电位计。梁上部和对应的下部电位计接在一起用来测量梁的扭转变形。用上下端部电位计的差值除以电位计的距离（沿梁高）。分析推算的二层梁端部变形曲线如图中的曲线所示。由图可以看出，分析的变形梁的变形曲线跟实验所得结果非常吻合。
根据模型A分析结果表明预示钢筋屈服的塑性铰只有两个，四个没有上部配筋的截面，到达屈服极限而开裂。图.10.给出了所有的塑性铰及开裂位置。
Response of a reinforced concrete infilled-frame structure to
removal of two adjacent columns
Mehrdad Sasani_
Northeastern University, 400 Snell Engineering Center, Boston, MA 02115, United States Received 27 June 2007; received in revised form 26 December 2007; accepted 24 January
2008
Available online 19 March 2008
Abstract
The response of Hotel San Diego, a six-story reinforced concrete infilled-frame structure, is evaluated following the simultaneous removal of two adjacent exterior columns. Analytical models of the structure using the Finite Element Method as well as the Applied Element Method are used to calculate global and local deformations. The analytical results show good agreement with experimental data. The structure resisted progressive collapse with a measured maximum vertical displacement of only one quarter of an inch (6.4 mm). Deformation propagation over the height of the structure and the dynamic load redistribution following the column removal are experimentally and analytically evaluated and described. The difference between axial and flexural wave propagations is discussed. Three-dimensional Vierendeel (frame) action of the transverse and longitudinal frames with the participation of infill walls is identified as the major mechanism for redistribution of loads in the structure. The effects of two potential brittle modes of failure (fracture of beam sections without tensile reinforcement and reinforcing bar pull out) are described. The response of the structure due to additional gravity loads and in the absence of infill walls is analytically evaluated.
c 2008 Elsevier Ltd. All rights reserved.
Keywords: Progressive collapse; Load redistribution; Load resistance; Dynamic response; Nonlinear analysis; Brittle failure
1. Introduction
As part of mitigation programs to reduce the likelihood of mass casualties following local damage in structures, the General Services Administration [1] and the Department of Defense [2] developed regulations to evaluate progressive collapse resistance of structures. ASCE/SEI 7 [3] defines progressive collapse as the spread of an initial local failure from element to element eventually resulting in collapse of an entire structure or a disproportionately large part of it. Following the approaches proposed by Ellingwood and
Leyendecker [4], ASCE/SEI 7 [3] defines two general methods for structural design of buildings to mitigate damage due to progressive collapse: indirect and direct design methods. General building codes and standards [3,5] use indirect design by increasing overall integrity of structures. Indirect design is also used in DOD [2]. Although the indirect design method can reduce the risk of progressive collapse [6,7] estimation ofpost-failure performance of structures designed based on such a method is not readily possible. One approach based on direct design methods to evaluate progressive collapse of structures is to study the effects of instantaneous removal of load-bearing elements, such as columns. GSA [1] and DOD [2] regulations require removal of one load bearing element. These regulations are meant to evaluate general integrity of structures and their capacity of redistributing the loads following severe damage to only one element. While such an approach provides insight as to the extent to which the structures are susceptible to progressive collapse, in reality, the initial damage can affect more than just one column. In this study, using analytical results that are verified against experimental data, the progressive collapse resistance of the Hotel San Diego is evaluated, following the simultaneous explosion (sudden removal) of two adjacent columns, one of which was a corner column. In order to explode the columns, explosives were inserted into predrilled holes in the columns. The columns were then well wrapped with a few layers of protective materials. Therefore, neither air blast nor flying fragments affected the structure.
2. Building characteristics
Hotel San Diego was constructed in 1914 with a south annex added in 1924. The annex included two separate buildings. Fig. 1 shows a south view of the hotel. Note that in the picture, the first and third stories of the hotel are covered with black fabric. The six story hotel had a non-ductile reinforced concrete (RC) frame structure with hollow clay tile exterior infill walls. The infills in the annex consisted of two wythes (layers) of clay tiles with a total thickness of about 8 in (203 mm). The height of the first floor was about 190–800 (6.00 m). The height of other floors and that of the top floor were 100–600 (3.20 m) and 160–1000 (5.13 m), respectively. Fig. 2 shows the second floor of one of the annex buildings. Fig. 3 shows a typical plan of this building, whose response following the simultaneous removal (explosion) of columns A2 and A3 in the first (ground) floor is evaluated in this paper. The floor system consisted of one-way joists running in the longitudinal direction (North–South), as shown in Fig. 3. Based on compression tests of two concrete samples, the average concrete compressive strength was estimated at about 4500 psi (31 MPa) for a standard concrete cylinder. The modulus of elasticity of concrete was estimated at 3820 ksi (26 300 MPa) [5]. Also, based on tension tests of two steel
samples having 1/2 in (12.7 mm) square sections, the yield and ultimate tensile strengths were found to be 62 ksi (427 MPa) and 87 ksi (600 MPa), respectively. The steel ultimate tensile strain was measured at 0.17. The modulus of elasticity of steel was set equal to 29 000 ksi (200 000 MPa). The building was scheduled to be demolished by implosion. As part of the demolition process, the infill walls were removed from the first and third floors. There was no live load in the building. All nonstructural elements including partitions, plumbing, and furniture were removed prior to implosion. Only beams, columns, joist floor and infill walls on the peripheral beams were present.
3. Sensors
Concrete and steel strain gages were used to measure changes in strains of beams and columns. Linear potentiometers were used to measure global and local deformations. The concrete strain gages were 3.5 in (90 mm) long having a maximum strain limit of ±0.02. The steel strain gages could measure up to a strain of ±0.20. The strain gages could operate up to a several hundred kHz sampling rate. The sampling rate used in the experiment was 1000 Hz. Potentiometers were used to capture rotation (integral of curvature over a length) of the beam end regions and global displacement in the building, as described later. The potentiometers had a resolution of about 0.0004 in (0.01 mm) and a maximum operational speed of about 40 in/s (1.0 m/s), while the maximum recorded speed in the experiment was about 14 in/s (0.35 m/s).
4. Finite element model
Using the finite element method (FEM), a model of the building was developed in the SAP2000 [8] computer program. The beams and columns are modeled with Bernoulli beam elements. Beams have T or L sections with effective flange width on each side of the web equal to four times the slab thickness [5]. Plastic hinges are assigned to all possible locations where steel bar yielding can occur, including the ends of elements as well as the reinforcing bar cut-off and bend locations. The characteristics of the plastic hinges are obtained using section analyses of the beams and columns and assuming a plastic hinge length equal to half of the section depth. The current version of SAP2000 [8] is not able to track formation of cracks in the elements. In order to find the proper flexural stiffness of sections, an iterative procedure is used as follows. First, the building is analyzed assuming all elements are uncracked. Then, moment demands in the elements are compared with their cracking bending moments, Mcr . The moment of inertia of beam and slab segments are reduced by a coefficient of 0.35 [5], where the demand exceeds the Mcr. The exterior beam cracking bending moments under negative and positive moments, are 516 k in (58.2 kN m) and 336 k in (37.9 kN m), respectively. Note that no cracks were formed in the columns. Then the building is reanalyzed and moment diagrams are re-evaluated. This procedure is repeated until all of the cracked regions are properly identified and modeled.
The beams in the building did not have top reinforcing bars except at the end regions (see Fig. 4). For instance, no top reinforcement was provided beyond the bend in beam A1–A2, 12 inches away from the face of column A1 (see Figs. 4 and 5). To model the potential loss of flexural strength in those sections, localized crack hinges were assigned at the critical locations where no top rebar was present. Flexural strengths of the hinges were set equal to Mcr. Such sections were assumed to lose their flexural strength when the imposed bending moments reached Mcr.
The floor system consisted of joists in the longitudinal direction (North–South). Fig. 6 shows the cross section of a typical floor. In order to account for potential nonlinear response of slabs and joists, floors are molded by beam elements. Joists are modeled with T-sections, having effective flange width on each side of the web equal to four times the slab thickness [5]. Given the large joist spacing between axes 2 and 3, two rectangular beam elements with 20-inch wide sections are used between the joist and the longitudinal beams of axes 2 and 3 to model the slab in the longitudinal direction. To model the behavior of the slab in the transverse direction, equally spaced parallel beams with 20-inch wide rectangular sections are used. There is a difference between the shear flow in the slab and that in the beam elements with rectangular sections modeling the slab. Because of this, the torsional stiffness is set
equal to one-half of that of the gross sections [9].
The building had infill walls on 2nd, 4th, 5th and 6th floors on the spandrel beams with some openings (i.e. windows and doors). As mentioned before and as part of the demolition procedure, the infill walls in the 1st and 3rd floors were removed before the test. The infill walls were made of hollow clay tiles, which were in good condition. The net area of the clay tiles was about 1/2 of the gross area. The in-plane action of the infill walls contributes to the building stiffness and strength and affects the building response. Ignoring the effects of the infill walls and excluding them in the model would result in underestimating the building stiffness and strength.
Using the SAP2000 computer program [8], two types of modeling for the infills are considered in this study: one uses two dimensional shell elements (Model A) and the other uses compressive struts (Model B) as suggested in FEMA356 [10] guidelines.
4.1. Model A (infills modeled by shell elements)
Infill walls are modeled with shell elements. However, the current version of the SAP2000 computer program includes only linear shell elements and cannot account for cracking. The tensile strength of the infill walls is set equal to 26 psi, with a modulus of elasticity of 644 ksi [10]. Because the formation ofcracks has a significant effect on the stiffness of the infill walls, the following iterative procedure is used to account for crack formation:
(1) Assuming the infill walls are linear and uncracked, a nonlinear time history analysis is run. Note that plastic hinges exist in the beam elements and the segments of the beam elements where moment demand exceeds the cracking moment have a reduced moment of inertia.
(2) The cracking pattern in the infill wall is determined by comparing stresses in the shells developed during the analysis with the tensile strength of infills.
(3) Nodes are separated at the locations where tensile stress exceeds tensile strength. These steps are continued until the crack regions are properly modeled.
4.2. Model B (infills modeled by struts)
Infill walls are replaced with compressive struts as described in FEMA 356 [10] guidelines. Orientations of the struts are determined from the deformed shape of the structure after column removal and the location of openings.
4.3. Column removal
Removal of the columns is simulated with the following procedure.
(1) The structure is analyzed under the permanent loads and the internal forces are determined at the ends of the columns, which will be removed.
(2) The model is modified by removing columns A2 and A3 on the first floor. Again the structure is statically analyzed under permanent loads. In this case, the internal forces at the ends of removed columns found in the first step are applied externally to the structure along with permanent loads. Note that the results of this analysis are identical to those of step 1.
(3) The equal and opposite column end forces that were applied in the second step are dynamically imposed on the ends of the removed column within one millisecond [11] to simulate the removal of the columns, and dynamic analysis is conducted.
4.4. Comparison of analytical and experimental results
The maximum calculated vertical displacement of the building occurs at joint A3 in the second floor. Fig. 7 shows the experimental and analytical (Model A) vertical displacements of this joint (the AEM results will be discussed in the next section). Experimental data is obtained using the recordings of three potentiometers attached to joint A3 on one of their ends, and to the ground on the other ends. The peak displacements obtained experimentally and analytically (Model A) are 0.242 in (6.1 mm) and 0.252 in (6.4 mm), respectively, which differ only by about 4%. The experimental and analytical times corresponding to peak displacement are 0.069 s and 0.066 s, respectively. The analytical results show a permanent displacement of about 0.208 in (5.3 mm), which is about 14% smaller than the corresponding experimental value of 0.242 in (6.1 mm). Fig. 8 compares vertical displacement histories of joint A3 in the second floor estimated analytically based on Models A and B. As can be seen, modeling infills with struts (Model B) results in a maximum vertical displacement of joint A3 equal to about 0.45 in (11.4 mm), which is approximately 80% larger than the value obtained from Model A. Note that the results obtained from Model A are in close agreement with experimental results (see Fig. 7), while Model B significantly overestimates the deformation of the structure. If the maximum vertical displacement were larger, the infill walls were more severely cracked and the struts were more completely formed, the difference between the results of the two models (Models A and B) would be smaller.
Fig. 9 compares the experimental and analytical (Model A) displacement of joint A2 in the second floor. Again, while the first peak vertical displacement obtained experimentally and analytically are in good agreement, the analytical permanent displacement under estimates the experimental value.
Analytically estimated deformed shapes of the structure at the maximum vertical displacement based on Model A are shown in Fig. 10 with a magnification factor of 200. The experimentally measured deformed shape over the end regions of beams A1–A2 and A3–B3 in the second floor
are represented in the figure by solid lines. A total of 14 potentiometers were located at the top and bottom of the end regions of the second floor beams A1–A2 and A3–B3, which were the most critical elements in load redistribution. The beam top and corresponding bottom potentiometer recordings were used to calculate rotation between the sections where the potentiometer ends were connected. This was done by first finding the difference between the recorded deformations at the top and bottom of the beam, and then dividing the value by the distance (along the height of the beam section) between the two potentiometers. The expected deformed shapes between the measured end regions of the
second floor beams are shown by dashed lines. As can be seen in the figures, analytically
estimated deformed shapes of the beams are in good agreement with experimentally obtained deformed shapes.
Analytical results of Model A show that only two plastic hinges are formed indicating rebar yielding. Also, four sections that did not have negative (top) reinforcement, reached cracking moment capacities and therefore cracked. Fig. 10 shows the locations of all the formed plastic hinges and cracks.
土木工程外文翻译.doc
项目成本控制 一、引言 项目是企业形象的窗口和效益的源泉。随着市场竞争日趋激烈，工程质量、文明施工要求不断提高，材料价格波动起伏，以及其他种种不确定因素的影响，使得项目运作处于较为严峻的环境之中。由此可见项目的成本控制是贯穿在工程建设自招投标阶段直到竣工验收的全过程，它是企业全面成本管理的重要环节，必须在组织和控制措施上给于高度的重视，以期达到提高企业经济效益的目的。 二、概述 工程施工项目成本控制，指在项目成本在成本发生和形成过程中，对生产经营所消耗的人力资源、物资资源和费用开支，进行指导、监督、调节和限制，及时预防、发现和纠正偏差从而把各项费用控制在计划成本的预定目标之内，以达到保证企业生产经营效益的目的。 三、施工企业成本控制原则 施工企业的成本控制是以施工项目成本控制为中心，施工项目成本控制原则是企业成本管理的基础和核心，施工企业项目经理部在对项目施工过程进行成本控制时，必须遵循以下基本原则。 3.1 成本最低化原则。施工项目成本控制的根本目的，在于通过成本管理的各种手段，促进不断降低施工项目成本，以达到可能实现最低的目标成本的要求。在实行成本最低化原则时，应注意降低成本的可能性和合理的成本最低化。一方面挖掘各种降低成本的能力，使可能性变为现实；另一方面要从实际出发，制定通过主观努力可能达到合理的最低成本水平。 3.2 全面成本控制原则。全面成本管理是全企业、全员和全过程的管理，亦称“三全”管理。项目成本的全员控制有一个系统的实质性内容，包括各部门、各单位的责任网络和班组经济核算等等，应防止成本控制人人有责，人人不管。项目成本的全过程控制要求成本控制工作要随着项目施工进展的各个阶段连续 进行，既不能疏漏，又不能时紧时松，应使施工项目成本自始至终置于有效的控制之下。 3.3 动态控制原则。施工项目是一次性的，成本控制应强调项目的中间控制，即动态控制。因为施工准备阶段的成本控制只是根据施工组织设计的具体内容确
土木工程类专业英文文献及翻译
PA VEMENT PROBLEMS CAUSED BY COLLAPSIBLE SUBGRADES By Sandra L. Houston,1 Associate Member, ASCE (Reviewed by the Highway Division) ABSTRACT: Problem subgrade materials consisting of collapsible soils are com- mon in arid environments, which have climatic conditions and depositional and weathering processes favorable to their formation. Included herein is a discussion of predictive techniques that use commonly available laboratory equipment and testing methods for obtaining reliable estimates of the volume change for these problem soils. A method for predicting relevant stresses and corresponding collapse strains for typical pavement subgrades is presented. Relatively simple methods of evaluating potential volume change, based on results of familiar laboratory tests, are used. INTRODUCTION When a soil is given free access to water, it may decrease in volume, increase in volume, or do nothing. A soil that increases in volume is called a swelling or expansive soil, and a soil that decreases in volume is called a collapsible soil. The amount of volume change that occurs depends on the soil type and structure, the initial soil density, the imposed stress state, and the degree and extent of wetting. Subgrade materials comprised of soils that change volume upon wetting have caused distress to highways since the be- ginning of the professional practice and have cost many millions of dollars in roadway repairs. The prediction of the volume changes that may occur in the field is the first step in making an economic decision for dealing with these problem subgrade materials. Each project will have different design considerations, economic con- straints, and risk factors that will have to be taken into account. However, with a reliable method for making volume change predictions, the best design relative to the subgrade soils becomes a matter of economic comparison, and a much more rational design approach may be made. For example, typical techniques for dealing with expansive clays include: (1) In situ treatments with substances such as lime, cement, or fly-ash; (2) seepage barriers and/ or drainage systems; or (3) a computing of the serviceability loss and a mod- ification of the design to "accept" the anticipated expansion. In order to make the most economical decision, the amount of volume change (especially non- uniform volume change) must be accurately estimated, and the degree of road roughness evaluated from these data. Similarly, alternative design techniques are available for any roadway problem. The emphasis here will be placed on presenting economical and simple methods for: (1) Determining whether the subgrade materials are collapsible; and (2) estimating the amount of volume change that is likely to occur in the 'Asst. Prof., Ctr. for Advanced Res. in Transp., Arizona State Univ., Tempe, AZ 85287. Note. Discussion open until April 1, 1989. To extend the closing date one month,
土木工程外文翻译
转型衰退时期的土木工程研究 Sergios Lambropoulosa[1], John-Paris Pantouvakisb, Marina Marinellic 摘要 最近的全球经济和金融危机导致许多国家的经济陷入衰退，特别是在欧盟的周边。这些国家目前面临的民用建筑基础设施的公共投资和私人投资显著收缩，导致在民事特别是在民用建筑方向的失业。因此，在所有国家在经济衰退的专业发展对于土木工程应届毕业生来说是努力和资历的不相称的研究，因为他们很少有机会在实践中积累经验和知识，这些逐渐成为过时的经验和知识。在这种情况下，对于技术性大学在国家经济衰退的计划和实施的土木工程研究大纲的一个实质性的改革势在必行。目的是使毕业生拓宽他们的专业活动的范围，提高他们的就业能力。 在本文中，提出了土木工程研究课程的不断扩大，特别是在发展的光毕业生的潜在的项目，计划和投资组合管理。在这个方向上，一个全面的文献回顾，包括ASCE体为第二十一世纪，IPMA的能力的基础知识，建议在其他：显著增加所提供的模块和项目管理在战略管理中添加新的模块，领导行为，配送管理，组织和环境等；提供足够的专业训练五年的大学的研究；并由专业机构促进应届大学生认证。建议通过改革教学大纲为土木工程研究目前由国家技术提供了例证雅典大学。 1引言 土木工程研究（CES）蓬勃发展，是在第二次世界大战后。土木工程师的出现最初是由重建被摧毁的巨大需求所致，目的是更多和更好的社会追求。但是很快，这种演变一个长期的趋势，因为政府为了努力实现经济发展，采取了全世界的凯恩斯主义的理论，即公共基础设施投资作为动力。首先积极的结果导致公民为了更好的生活条件（住房，旅游等）和增加私人投资基础设施而创造机会。这些现象再国家的发展中尤为为明显。虽然前景并不明朗（例如，世界石油危机在70年代），在80年代领先的国家采用新自由主义经济的方法（如里根经济政策），这是最近的金融危机及金融危机造成的后果（即收缩的基础设施投资，在技术部门的高失业率），消除发展前途无限的误区。 技术教育的大学所认可的大量研究土木工程部。旧学校拓展专业并且新的学校建成，并招收许多学生。由于高的职业声望，薪酬，吸引高质量的学校的学生。在工程量的增加和科学技术的发展，导致到极强的专业性，无论是在研究还是工作当中。结构工程师，液压工程师，交通工程师等，都属于土木工程。试图在不同的国家采用专业性的权利，不同的解决方案，，从一个统一的大学学历和广泛的专业化的一般职业许可证。这个问题在许多其他行业成为关键。国际专业协会的专家和机构所确定的国家性检查机构，经过考试后，他们证明不仅是行业的新来者，而且专家通过时间来确定进展情况。尽管在很多情况下，这些证书虽然没有国家接受，他们赞赏和公认的世界。 在试图改革大学研究（不仅在土木工程）更接近市场需求的过程中，欧盟确定了1999博洛尼亚宣言，它引入了一个二能级系统。第一级度（例如，一个三年的学士）是进入
土木工程外文文献翻译
专业资料 学院： 专业：土木工程 姓名： 学号： 外文出处：Structural Systems to resist (用外文写) Lateral loads 附件：1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文 抗侧向荷载的结构体系 常用的结构体系 若已测出荷载量达数千万磅重，那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。 这并不是说没有进行宏观构思的余地。实际上，正是因为有了这种宏观的构思，新奇的高层建筑体系才得以发展，可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了。 如果忽略一些与建筑材料密切相关的概念不谈，高层建筑里最为常用的结构体系便可分为如下几类： 1.抗弯矩框架。 2.支撑框架，包括偏心支撑框架。 3.剪力墙，包括钢板剪力墙。 4.筒中框架。 5.筒中筒结构。 6.核心交互结构。 7. 框格体系或束筒体系。 特别是由于最近趋向于更复杂的建筑形式，同时也需要增加刚度以抵抗几力和地震力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。 将这些构件结合起来的方法正是高层建筑设计方法的本质。其结合方式需要在考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。这并
不是说富于想象力的结构设计就能够创造出伟大建筑。正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。 虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。设计方法的本质贯穿于整个讨论。设计方法的本质贯穿于整个讨论中。 抗弯矩框架 抗弯矩框架也许是低，中高度的建筑中常用的体系，它具有线性水平构件和垂直构件在接头处基本刚接之特点。这种框架用作独立的体系，或者和其他体系结合起来使用，以便提供所需要水平荷载抵抗力。对于较高的高层建筑，可能会发现该本系不宜作为独立体系，这是因为在侧向力的作用下难以调动足够的刚度。 我们可以利用STRESS，STRUDL 或者其他大量合适的计算机程序进行结构分析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地，由于柱梁节点固有柔性，并且由于初步设计应该力求突出体系的弱点，所以在初析中使用框架的中心距尺寸设计是司空惯的。当然，在设计的后期阶段，实际地评价结点的变形很有必要。 支撑框架 支撑框架实际上刚度比抗弯矩框架强，在高层建筑中也得到更广泛的应用。这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色，它通常与其他体系共同用于较高的建筑，并且作为一种独立的体系用在低、中高度的建筑中。
土木工程岩土类毕业设计外文翻译
姓名： 学号： 10447425 X X 大学 毕业设计（论文）外文翻译 （2014届） 外文题目Developments in excavation bracing systems 译文题目开挖工程支撑体系的发展 外文出处Tunnelling and Underground Space Technology 31 (2012) 107–116 学生XXX 学院XXXX 专业班级XXXXX 校内指导教师XXX 专业技术职务XXXXX 校外指导老师专业技术职务 二○一三年十二月
开挖工程支撑体系的发展 1.引言 几乎所有土木工程建设项目（如建筑物，道路，隧道，桥梁，污水处理厂，管道，下水道）都涉及泥土挖掘的一些工程量。往往由于由相邻的结构，特性线，或使用权空间的限制，必须要一个土地固定系统，以允许土壤被挖掘到所需的深度。历史上，许多挖掘支撑系统已经开发出来。其中，现在比较常见的几种方法是：板桩，钻孔桩墙，泥浆墙。 土地固定系统的选择是由技术性能要求和施工可行性（例如手段，方法）决定的，包括执行的可靠性，而成本考虑了这些之后，其他问题也得到解决。通常环境后果（用于处理废泥浆和钻井液如监管要求）也非常被关注（邱阳、1998）。 土地固定系统通常是建设项目的较大的一个组成部分。如果不能按时完成项目，将极大地影响总成本。通常首先建造支撑，在许多情况下，临时支撑系统是用于支持在挖掘以允许进行不断施工，直到永久系统被构造。临时系统可以被去除或留在原处。 打桩时，因撞击或振动它们可能会被赶入到位。在一般情况下，振动是最昂贵的方法，但只适合于松散颗粒材料，土壤中具有较高电阻（例如，通过鹅卵石）的不能使用。采用打入桩系统通常是中间的成本和适合于软沉积物（包括粘性和非粘性），只要该矿床是免费的鹅卵石或更大的岩石。 通常，垂直元素（例如桩）的前安装挖掘工程和水平元件（如内部支撑或绑回）被安装为挖掘工程的进行下去，从而限制了跨距长度，以便减少在垂直开发弯矩元素。在填充情况下，桩可先设置，从在斜坡的底部其嵌入悬挑起来，安装作为填充进步水平元素（如搭背或土钉）。如果滞后是用来保持垂直元素之间的土壤中，它被安装为挖掘工程的进行下去，或之前以填补位置。 吉尔- 马丁等人（2010）提供了一个数值计算程序，以获取圆形桩承受轴向载荷和统一标志（如悬臂桩）的单轴弯矩的最佳纵筋。他们开发的两种优化流程：用一个或两个直径为纵向钢筋。优化增强模式允许大量减少的设计要求钢筋的用量，这些减少纵向钢筋可达到50％相对传统的，均匀分布的加固方案。 加固桩集中纵向钢筋最佳的位置在受拉区。除了节约钢筋，所述非对称加强钢筋图案提高抗弯刚度，通过增加转动惯量的转化部分的时刻。这种增加的刚性可能会在一段时间内增加的变形与蠕变相关的费用。评估相对于传统的非对称加强桩的优点，对称，钢筋桩被服务的条件下全面测试来完成的，这种试验是为了验证结构的可行性和取得的变形的原位测量。 基于现场试验中，用于优化的加强图案的优点浇铸钻出孔（CIDH）在巴塞罗那的
土木工程专业外文文献及翻译
（ 二 〇 一 二 年 六 月 外文文献及翻译 题 目： About Buiding on the Structure Design 学生姓名： 学 院：土木工程学院 系 别：建筑工程系 专 业：土木工程(建筑工程方向) 班 级：土木08-4班 指导教师：
英文原文： Building construction concrete crack of prevention and processing Abstract The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processing Foreword Concrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the
土木工程毕业设计外文文献翻译修订版
土木工程毕业设计外文文献翻译修订版 IBMT standardization office【IBMT5AB-IBMT08-IBMT2C-ZZT18】
外文文献翻译 Reinforced Concrete （来自《土木工程英语》） Concrete and reinforced concrete are used as building materials in every country. In many, including the United States and Canada, reinforced concrete is a dominant structural material in engineered construction. The universal nature of reinforced concrete construction stems from the wide availability of reinforcing bars and the constituents of concrete, gravel, sand, and cement, the relatively simple skills required in concrete construction, and the economy of reinforced concrete compared to other forms of construction. Concrete and reinforced concrete are used in bridges, buildings of all sorts underground structures, water tanks, television towers, offshore oil exploration and production structures, dams, and even in ships. Reinforced concrete structures may be cast-in-place concrete, constructed in their final location, or they may be precast concrete produced in a factory and erected at the construction site. Concrete structures may be severe and functional in design, or the shape and layout and be whimsical and artistic. Few other building materials off the architect and engineer such versatility and scope. Concrete is strong in compression but weak in tension. As a result, cracks develop whenever loads, or restrained shrinkage of temperature changes, give rise to tensile stresses in excess of the tensile strength of the concrete. In
土木工程外文翻译参考3篇
学校 毕业设计（论文）附件 外文文献翻译 学号： xxxxx 姓名： xxx 所在系别： xxxxx 专业班级： xxx 指导教师： xxxx 原文标题： Building construction concrete crack of prevention and processing 2012年月日 .
建筑施工混凝土裂缝的预防与处理1 摘要 混凝土的裂缝问题是一个普遍存在而又难于解决的工程实际问题，本文对混凝土工程中常见的一些裂缝问题进行了探讨分析，并针对具体情况提出了一些预防、处理措施。 关键词：混凝土裂缝预防处理 前言 混凝土是一种由砂石骨料、水泥、水及其他外加材料混合而形成的非均质脆性材料。由于混凝土施工和本身变形、约束等一系列问题，硬化成型的混凝土中存在着众多的微孔隙、气穴和微裂缝，正是由于这些初始缺陷的存在才使混凝土呈现出一些非均质的特性。微裂缝通常是一种无害裂缝，对混凝土的承重、防渗及其他一些使用功能不产生危害。但是在混凝土受到荷载、温差等作用之后，微裂缝就会不断的扩展和连通，最终形成我们肉眼可见的宏观裂缝，也就是混凝土工程中常说的裂缝。 混凝土建筑和构件通常都是带缝工作的，由于裂缝的存在和发展通常会使内部的钢筋等材料产生腐蚀，降低钢筋混凝土材料的承载能力、耐久性及抗渗能力，影响建筑物的外观、使用寿命，严重者将会威胁到人们的生命和财产安全。很多工程的失事都是由于裂缝的不稳定发展所致。近代科学研究和大量的混凝土工程实践证明，在混凝土工程中裂缝问题是不可避免的，在一定的范围内也是可以接受的，只是要采取有效的措施将其危害程度控制在一定的范围之内。钢筋混凝土规范也明确规定：有些结构在所处的不同条件下，允许存在一定宽度的裂缝。但在施工中应尽量采取有效措施控制裂缝产生，使结构尽可能不出现裂缝或尽量减少裂缝的数量和宽度，尤其要尽量避免有害裂缝的出现，从而确保工程质量。 混凝土裂缝产生的原因很多，有变形引起的裂缝：如温度变化、收缩、膨胀、不均匀沉陷等原因引起的裂缝；有外载作用引起的裂缝；有养护环境不当和化学作用引起的裂缝等等。在实际工程中要区别对待，根据实际情况解决问题。 混凝土工程中常见裂缝及预防: 1.干缩裂缝及预防 干缩裂缝多出现在混凝土养护结束后的一段时间或是混凝土浇筑完毕后的一周左右。水泥浆中水分的蒸发会产生干缩，且这种收缩是不可逆的。干缩裂缝的产生主要是由于混凝土内外水分蒸发程度不同而导致变形不同的结果：混凝土受外部条件的影响，表面水分损失过快，变形较大，内部湿度变化较小变形较小，较大的表面干缩变形受到混凝土内部约束，产生较大拉应力而产生裂缝。相对湿度越低，水泥浆体干缩越大，干缩裂缝越易产 1原文出处及作者：《加拿大土木工程学报》
土木工程毕业设计外文翻译最终中英文
7 Rigid-Frame Structures A rigid-frame high-rise structure typically comprises parallel or orthogonally arranged bents consisting of columns and girders with moment resistant joints. Resistance to horizontal loading is provided by the bending resistance of the columns, girders, and joints. The continuity of the frame also contributes to resisting gravity loading, by reducing the moments in the girders. The advantages of a rigid frame are the simplicity and convenience of its rectangular form.Its unobstructed arrangement, clear of bracing members and structural walls, allows freedom internally for the layout and externally for the fenestration. Rig id frames are considered economical for buildings of up to' about 25 stories, above which their drift resistance is costly to control. If, however, a rigid frame is combined with shear walls or cores, the resulting structure is very much stiffer so that its height potential may extend up to 50 stories or more. A flat plate structure is very similar to a rigid frame, but with slabs replacing the girders As with a rigid frame, horizontal and vertical loadings are resisted in a flat plate structure by the flexural continuity between the vertical and horizontal components. As highly redundant structures, rigid frames are designed initially on the basis of approximate analyses, after which more rigorous analyses and checks can be made. The procedure may typically inc lude the following stages: 1. Estimation of gravity load forces in girders and columns by approximate method. 2. Preliminary estimate of member sizes based on gravity load forces with arbitrary increase in sizes to allow for horizontal loading. 3. Approximate allocation of horizontal loading to bents and preliminary analysis of member forces in bents. 4. Check on drift and adjustment of member sizes if necessary. 5. Check on strength of members for worst combination of gravity and horizontal loading, and adjustment of member sizes if necessary. 6. Computer analysis of total structure for more accurate check on member strengths and drift, with further adjustment of sizes where required. This stage may include the second-order P-Delta effects of gravity loading on the member forces and drift.. 7. Detailed design of members and connections.
土木工程外文翻译5
PROJECTCOSTCONTROL INTRODUCTION project a corporate image window and effectiveness of the source. With increasingly fierce market competition, the quality of work and the construction of civilizations rising material prices fluctuations. uncertainties and other factors, make the project operational in a relatively tough environment. So the cost of control is through the building of the project since the bidding phase of acceptance until the completion of the entire process, It is a comprehensive enterprise cost management an important part, we must organize and control measures in height to the attention with a view to improving the economic efficiency of enterprises to achieve the purpose. 2, outlining the construction project cost control, the cost of the project refers to the cost and process of formation occurred, on the production and operation of the amount of human resources, material resources and expenses, guidance, supervision, regulation and restrictions, in a timely manner to prevent, detect and correct errors in order to control costs in all project costs within the intended target. to guarantee the production and operation of enterprises benefits. 4, the construction cost control measures cost control measures. Reduce the cost of construction projects means, we should not only increase revenue is also reducing expenditure, or both also increase savings. Cutting expenditure is not only revenue, or revenue not only to cut expenditure, it is impossible to achieve the aim of reducing costs, at least there is no ideal lower cost effective.
土木工程毕业设计中英文翻译
附录：中英文翻译 英文部分： LOADS Loads that act on structures are usually classified as dead loads or live loads are fixed in location and constant in magnitude throughout the life of the the self-weight of a structure is the most important part of the structure and the unit weight of the density varies from about 90 to 120 pcf (14 to 19 KN/m)for lightweight concrete,and is about 145 pcf (23 KN/m)for normal calculating the dead load of structural concrete,usually a 5 pcf (1 KN/m)increment is included with the weight of the concrete to account for the presence of the reinforcement. Live loads are loads such as occupancy,snow,wind,or traffic loads,or seismic may be either fully or partially in place,or not present at may also change in location. Althought it is the responsibility of the engineer to calculate dead loads,live loads are usually specified by local,regional,or national codes and sources are the publications of the American National Standards Institute,the American Association of State Highway and Transportation Officials and,for wind loads,the recommendations of the ASCE Task Committee on Wind Forces. Specified live the loads usually include some allowance for overload,and may include measures such as posting of maximum loads will not be is oftern important to distinguish between the
土木工程岩土类毕业设计外文翻译
学号： 10447425 X X 大学 毕业设计（论文）外文翻译 （2014届） 外文题目 Developments in excavation bracing systems 译文题目开挖工程支撑体系的发展 外文出处 Tunnelling and Underground Space Technology 31 (2012) 107–116 学生 XXX 学院 XXXX 专业班级 XXXXX 校内指导教师 XXX 专业技术职务 XXXXX 校外指导老师专业技术职务 二○一三年十二月
开挖工程支撑体系的发展 1.引言 几乎所有土木工程建设项目（如建筑物，道路，隧道，桥梁，污水处理厂，管道，下水道）都涉及泥土挖掘的一些工程量。往往由于由相邻的结构，特性线，或使用权空间的限制，必须要一个土地固定系统，以允许土壤被挖掘到所需的深度。历史上，许多挖掘支撑系统已经开发出来。其中，现在比较常见的几种方法是：板桩，钻孔桩墙，泥浆墙。 土地固定系统的选择是由技术性能要求和施工可行性（例如手段，方法）决定的，包括执行的可靠性，而成本考虑了这些之后，其他问题也得到解决。通常环境后果（用于处理废泥浆和钻井液如监管要求）也非常被关注（邱阳、1998）。 土地固定系统通常是建设项目的较大的一个组成部分。如果不能按时完成项目，将极大地影响总成本。通常首先建造支撑，在许多情况下，临时支撑系统是用于支持在挖掘以允许进行不断施工，直到永久系统被构造。临时系统可以被去除或留在原处。 打桩时，因撞击或振动它们可能会被赶入到位。在一般情况下，振动是最昂贵的方法，但只适合于松散颗粒材料，土壤中具有较高电阻（例如，通过鹅卵石）的不能使用。采用打入桩系统通常是中间的成本和适合于软沉积物（包括粘性和非粘性），只要该矿床是免费的鹅卵石或更大的岩石。 通常，垂直元素（例如桩）的前安装挖掘工程和水平元件（如内部支撑或绑回）被安装为挖掘工程的进行下去，从而限制了跨距长度，以便减少在垂直开发弯矩元素。在填充情况下，桩可先设置，从在斜坡的底部其嵌入悬挑起来，安装作为填充进步水平元素（如搭背或土钉）。如果滞后是用来保持垂直元素之间的土壤中，它被安装为挖掘工程的进行下去，或之前以填补位置。 吉尔- 马丁等人（2010）提供了一个数值计算程序，以获取圆形桩承受轴向载荷和统一标志（如悬臂桩）的单轴弯矩的最佳纵筋。他们开发的两种优化流程：用一个或两个直径为纵向钢筋。优化增强模式允许大量减少的设计要求钢筋的用量，这些减少纵向钢筋可达到50％相对传统的，均匀分布的加固方案。 加固桩集中纵向钢筋最佳的位置在受拉区。除了节约钢筋，所述非对称加强钢筋图案提高抗弯刚度，通过增加转动惯量的转化部分的时刻。这种增加的刚性可能会在一段时间内增加的变形与蠕变相关的费用。评估相对于传统的非对称加强桩的优点，对称，钢筋桩被服务的条件下全面测试来完成的，这种试验是为了验证结构的可行性和取得的变形的原位测量。 基于现场试验中，用于优化的加强图案的优点浇铸钻出孔（CIDH）在巴塞罗那的几个非对称加强桩的施工过程中观察到混凝土桩沿与测得的变形的结果在常规和描述优化桩。实验证据表明，非对称地增强桩变形比观察到在常规增强那些小。两桩类型（对称和非对称）具有相同的直径，并设计为抵抗基于极限强度设计相同的弯曲力矩;离散杆的尺寸和使用的条全数字的，导致类似的名义抗弯强度。