预应力高强不锈钢绞线网-高性能砂浆抗弯加固试验研究

聂建国^1，2　陶　巍^1，2　张天申^1，2
（1. 清华大学土木工程系，北京100084；
2. 清华大学结构工程与振动教育部重点实验室，北京100084）

摘要：在以往试验研究的基础上，对钢绞线施加预应力，以研究预应力高强不锈钢绞线网-高性能砂浆加固技术对RC梁的适用性。对5根预应力高强不锈钢绞线网-高性能砂浆加固的钢筋混凝土梁和1根对比梁进行了抗弯试验研究，试验结果表明，采用预应力措施有效地提高了梁的抗弯承载力和刚度，较好地约束了裂缝的发展。同时提出利用该种加固方法进行抗弯加固的承载力设计计算公式。计算结果与试验结果吻合较好。另外，还就高强不锈钢绞线网的预应力张拉、预应力损失等进行试验研究，提出完整的预应力高强不锈钢绞线网加固受弯构件的施工工艺，并给出采用不同张拉方法时预应力有效值系数的取值，使得该种加固方法能够更好地应用于实际工程中。
关键词：RC梁抗弯加固；预应力高强不锈钢绞线网；高性能砂浆；试验研究

Experimental study on the flexural behavior of RC beams strengthened
with prestressed stainless steel wire mesh and permeability polymer mortar

Nie Jianguo^1,2　Tao Wei^1,2　Zhang Tianshen^1,2
（1.Department of Civil Engineering， Tsinghua University， Beijing 100084， China;
2. Key Laboratory of Structural Engineering and Vibration of China Education Ministry， Tsinghua University， Beijing 100084，China）

Abstract: A study is conducted on the flexural performance of RC beams strengthened with prestressed high-strength stainless steel wire and permeable mortar, based on existing test data, to assess the suitability of such strengthening technique to RC beams. A total of five RC beams strengthened with prestressed stainless steel wire and permeable mortar and one comparative RC beam were tested under different types of loading. The experimental results indicated that the flexural load capacity and stiffness were increased effectively and the propagation of cracks was reduced obviously by the rehabilitation. The design formulae of flexural load capacity are developed. The calculated results are in good agreement with the experimental data. The strengthening technology with prestressed high-strength stainless steel wire and permeable mortar was presented. The virtual value coefficient is discussed.
Keywords: flexural strengthening of RC beam; prestressed stainless steel wire mesh; permeability polymer mortar; experimental study
E-mail: taow03@mails.tsinghua.edu.cn

混合控制结构的多维动力分析与优化设计

张延年^1，2　李宏男¹
（1.大连理工大学，辽宁大连116024；2.沈阳建筑大学，辽宁沈阳110168）

摘要：为了改善滑移隔震结构的减震效果，并研究双向耦合地震作用对减震效果的影响。提出3种磁流变阻尼器（MRD）与滑移隔震混合方案，建立双向耦合地震作用下MRD与滑移隔震混合控制结构的动力分析模型，对6层MRD与滑移隔震混合控制结构进行地震反应分析。结果表明3种混合方案在不同工况荷载作用下的相对加速度峰值、相对速度峰值、相对位移峰值和层间剪力峰值分别比滑移隔震结构有不同程度的降低。当考虑竖向地震作用的存在时，随着竖向地震作用的增大，结构的地震反应有小幅度的增加，但各混合方案在各种工况下的各项地震反应均得到较好的控制，而混合方案3的控制效果更加明显。建立MRD与滑移隔震混合控制结构优化设计模型，采用IHGA程序对混合方案3进行优化设计。结果表明，MRD与滑移隔震混合控制结构的各项地震反应均得到更好的控制。
关键词：混合控制；滑移隔震结构；MRD；耦合地震作用；结构优化；改进遗传算法；混合遗传算法

Structural hybrid control with MRD and sliding base-isolation under bi-directional earthquakes

Zhang Yannian^{1, 2}　Li Hongnan¹
（1.Dalian University of Technology, Dalian 116024, China;
2.Shenyang Jianzhu University, Shenyang 110168, China）

Abstract: In order to improve the effect of shock absorption of sliding base-isolated structures, and to study the influence of the coupled action of earthquake in both horizontal and vertical directions on vibration control structures, three types of hybrid schemes with magnetorheological damper (MRD) and sliding base-isolation are proposed. The theory of hybrid structure with MRD and sliding base-isolation under the coupled action of earthquakes in both horizontal and vertical directions is studied. A dynamic analysis model for hybrid structures is formulated, and the kinematic differential equation developed. Seismic response analysis of a 6-storey hybrid structure with MRD and sliding base-isolation is carried out. Comparison of the results of dynamic analysis indicates that various seismic responses of the three hybrid schemes with MRD and sliding base-isolation under various loading conditions have better control than sliding isolated structures, and that the third hybrid scheme is the best. An optimal model for hybrid structure with MRD and sliding base-isolation is established to optimize the control on the various earthquake responses of hybrid structures with MRD and sliding base-isolation.
Keywords: hybrid control；sliding base-isolated structure；magnetorheological damper；coupling effect of earthquake；structural optimization；improved genetic algorithm；hybrid genetic algorithm
E-mail: zyntiger@163.com

受扰高层建筑的风致响应分析

周晅毅　黄　鹏　顾　明
（同济大学土木工程防灾国家重点实验室，上海200092）

摘要：受扰状态下高层建筑的静动力响应明显不同于单体建筑。以一实际姊妹塔楼为研究对象，根据风洞试验中获得的风压分布结果，计算塔楼结构的风致响应。风洞试验及结构响应计算不仅考虑了两栋塔楼同时存在的情况，还考虑一栋塔楼先期建成，另一塔楼尚未建造的情况。细致分析了不同风向下结构的平均及脉动位移响应、静动力干扰因子的特点。结果表明，施扰建筑位于受扰建筑正前方时具有最大的干扰效应，此时受扰塔楼的总位移峰值最小；而当受扰建筑处于施扰建筑下游时，在风向偏斜时，受扰塔楼的总位移峰值最大。
关键词：高层建筑；干扰效应；模态叠加法；结构风致振动

Wind-induced interference effects on a tall building with two towers

Zhou Xuanyi　Huang Peng　Gu Ming
（State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai200092, China）

Abstract: Due to the interference of neighboring buildings, the static and dynamic wind-induced responses of tall buildings are considerably different from those of isolated buildings. The dynamic interference effects between two tall buildings are studied. The case in which only one building exists without the other is also analyzed. The wind-induced dynamic responses of the buildings are computed in frequency domain by using mode superposition method, based on the wind pressure distributions on the buildings from wind tunnel tests on the rigid models. The characteristics of the wind-induced displacement responses and static/dynamic interference factors for different wind directions are investigated. The study indicates that the upstream tower located just in the front of the interfered building has the greatest influence upon the downstream tower, whose total peak displacements are the smallest. When the principal building is located upstream with an oblique wind direction, the strongest interference effect is reached, with the largest total peak displacement of the upstream building.
Keywords: tall building; interference effect; mode superposition method; wind-induced vibration
E-mail: zhouxytj@mail.tongji.edu.cn

承载开闭钢屋盖的预应力混凝土看台结构抗震性能研究

陈以一　张大照　薛伟辰　卢文胜
（同济大学，上海200092）

摘要：为了深入探索承载开闭钢屋盖的预应力混凝土看台结构的抗震性能，针对上海旗忠森林体育城网球中心开闭钢屋盖与预应力混凝土看台组成的结构体系，继振动台模型试验后，采用弹塑性有限元分析，对比研究了主振型为扭转的结构体系的反应特点、屋盖闭合与开启状态对预应力结构抗震性能的影响、闭环式倒锥台空间框架结构体系的弹塑性地震反应规律和破坏模式。研究发现：屋盖的不同状态影响结构的振动特性和地震反应；以扭转为主振型的闭环式看台结构在水平地震作用下的响应模式为平动形式；预应力看台结构罕遇地震后的整体性能良好；闭环式倒锥台空间框架构形限制了大震下结构的侧移，相对于平行式框架，能提高对重力荷载的抗倒塌能力。本研究增进了对有开闭屋盖的结构体系及闭环式框架结构体系的抗震性能认识，有助于这类结构的设计。
关键词：开闭钢屋盖；预应力混凝土；抗震性能；破坏模式；弹塑性反应分析；振动台试验

Seismic performance of a prestressed concrete stadium structure
supporting a retractable steel roof

Chen Yiyi　Zhang Dazhao　Xue Weichen　Lu Wensheng
（Tongji University, Shanghai200092, China）

Abstract: In order to explore the seismic performance of a prestressed concrete stadium structure supporting a retractable steel roof, the structure of the Shanghai Qizhong Tennis Center, consisting of a retractable steel roof and a prestressed concrete stadium, is studied by using elasto-plastic finite element analysis and shaking table test. The following issues are investigated: the effects of the roof configurations in opening and closing and the pre-stress on the structural seismic response, the general behavior and failure mechanism of the stadium spatial frame systems featured with circularly arranged columns and inverse-cone stands. It is found that the roof status has great effect on the natural period, vibration mode and seismic response of the entire structure, the stand response to horizontal seismic excitation is stronger in roof opening configuration than in closing configuration and the response mode is dominantly translational rather than rotational, though the stand is characterized by its fundamentally torsional vibration mode. The study indicates that the prestressed inverse-cone stands keep the system from global side-sway collapse under gravity loads, even in case that most columns lost moment capacity.?
Keywords: retractable steel roof；prestressed concrete；seismic performance；failure mode；inelastic response；shaking table test
E-mail: yiyichen@mail.tongji.edu.cn

强震下单层柱面网壳损伤及失效机理研究

支旭东　范　峰　沈世钊
（哈尔滨工业大学，黑龙江哈尔滨150090）

摘要：基于结构损伤理论，对单层柱面网壳在强震下的失效机理进行研究。单层柱面网壳在强震下不仅会发生动力失稳，也可能由于过度塑性发展导致动力强度破坏的模式。对于动力强度失效的研究，应当在分析中考虑材料损伤累积以及断裂效应的影响。为在有限元分析中包含这一影响因素，编制了基于通用有限元软件ABAQUS的用户材料子程序，具有较高的计算精度和较好的收敛性。应用其对单层柱面网壳在强震下的响应进行参数研究，并与基于理想弹塑性材料时的响应对比，讨论考虑材料损伤对网壳失效特征的影响。将单层柱面网壳在强震下失效时刻的多项特征响应进行统计分析，拟合了能够表征网壳损伤程度的损伤模型，建立单层柱面网壳在强震下的失效判别准则。针对实际工程抗震设计中采用损伤累积本构模型计算的困难，提出网壳结构失效极限的简化判别方法。
关键词：单层柱面网壳；地震作用；动力强度破坏；损伤累积

Failure and damage of single-layer reticulated cylindrical shells under earthquakes

Zhi Xudong　Fan Feng　Shen Shizhao
（Harbin Institute of Technology, Harbin150090, China）

Abstract: The failure mechanism of single-layer reticulated shells subjected to earthquakes is addressed on the basis of the structural damage theory. Dynamic instability collapse of single-layer reticulated cylindrical shells subjected to severe earthquakes is not the only form of dynamic failure, strength failure resulted from excessive development of plastic deformation may also occur. The effect of material damage accumulation and fraction should be considered in the analysis of dynamic strength failure of reticulated shells. The user material subroutine in ABAQUS is compiled for analyzing reticulated shells subjected to dynamic loads with the consideration of damage accumulation, and the user subroutine is validated and proved be excellent in convergence. Using this subroutine, the failure characteristics of single-layer reticulated cylindrical shells under severe earthquakes is studied with parameterization, and the influence of damage accumulation is discussed. According to the characteristic responses of single-layer reticulated cylindrical shells at failure state, the damage mode indicating the damage level of the reticulated shells is fitted, and the strength failure criterion is proposed for distinguishing the ultimate load of earthquake failure. A simplified method for obtaining the ultimate load is proposed, because it is difficult to calculate structural damage index with the consideration of damage accumulation in anti-seismic design.
Keywords: single-layer reticulated cylindrical shell; earthquake; dynamic strength failure; damage accumulation
E-mail: zhixudong@hit.edu.cn

圆钢管轻集料混凝土构件抗弯性能的试验研究

吉伯海　胡正清　陈甲树　周文杰
（河海大学，江苏南京210098）

摘要：进行了21根钢管轻集料混凝土以及8根空钢管的纯弯试验。通过对试件在加载过程中的挠度及表面应变的测试分析，研究钢管轻集料混凝土构件在弯矩作用下的宏观变形特征、弯矩-曲率关系和破坏模式，分析了轻集料混凝土强度、含钢率、剪跨比等主要参数对构件抗弯性能的影响。试验研究结果表明，钢管轻集料混凝土构件在纯弯矩的作用下，其宏观变形特征和破坏形态与钢管普通混凝土构件相似；内填的轻集料混凝土可以大大延缓或避免钢管局部屈曲的发生，钢管轻集料混凝土的极限抗弯承载力较空钢管提高了20%~30%，抗弯刚度也有所提高；在钢管和轻集料混凝土相互作用下，钢管轻集料混凝土受弯试件具有较高的抗弯承载力和良好的延性性能；含钢率是影响钢管轻集料混凝土抗弯承载力和初始抗弯刚度的主要因素，含钢率越大，初始刚度越大和构件极限抗弯承载力也越大；而内填混凝土强度和剪跨比对构件抗弯承载力的影响较小；与钢管普通混凝土研究结果的对比分析表明，在相同条件下，钢管轻集料混凝土与钢管普通混凝土的极限抗弯承载力大致相当。
关键词： 钢管轻集料混凝土；含钢率；纯弯荷载；抗弯承载力

An experimental study on the behavior of lightweight aggregate
concrete filled circular steel tubes under pure bending load

Ji Bohai? Hu Zhengqing? Chen Jiashu? Zhou Wenjie
（Hohai University, Nanjing 210098, China）

Abstract: Twenty-one lightweight aggregate concrete filled steel tubes (LACFST) and eight steel tubes were tested under pure bending load. The macroscopic characteristics of deformation, moment-curvature curves and failure mode were studied by analyzing the deflections and surface strains of the specimens. In addition, the effects of concrete strength, steel ratio and shear-span ratio on the bending capacity of the members were discussed. The test results indicate that the macroscopic characteristics of deformation, moment-curvature curves and failure mode of LACFST are similar to those of common concrete filled steel tubes (CFST). Not only the buckling of the steel tube is suspended or even avoided due to lightweight aggregate core concrete, but also the bending capacity and rigidity are enhanced. The steel ratio has the most significant effect on the flexural capacity of the member, while the concrete strength and shear-span ratio have little effect．Comparison between the current work and the published data were carried out and it is found that the ultimate bearing capability of lightweight aggregate concrete filled steel tubes is close to that of normal concrete filled steel tube.
Keywords: lightweight aggregate concrete filled steel tube；steel ratio；pure bending load；flexural capacity
E-mail: bhji@hhu.edu.cn

CFRP维修加固局部受损木柱的试验研究

许清风　朱　雷
（上海市建筑科学研究院，上海200032）

摘要：木柱在长期使用过程中易发生底端腐朽或局部损伤。共进行13根木柱采用局部顺纹木块替换并用CFRP布包裹的试验研究，取得了较好的维修加固效果。研究结果表明，受损木柱的极限承载力明显降低，降低幅度大于其截面损失幅度，且破坏呈明显的偏心受力特征；局部受损处用完好顺纹木块替换并用CFRP布包裹后，其受压承载力和延性性能可得到完全恢复；但采用横纹木块替换时，其受压承载力不能得到完全恢复。顺纹木块局部替换并用CFRP布包裹维修加固局部受损木柱是行之有效的方法，可用于木结构维修加固的工程实践。
关键词：木柱；碳纤维；维修加固；损伤；承载力；延性

An experimental study on partially-damaged wood columns
repaired and strengthened with CFRP

Xu Qingfeng　Zhu Lei
（Shanghai Research Institute of Building Sciences, Shanghai200032, China）

Abstract: Wood is a traditional construction material with excellent properties for a variety of applications, and most of the Chinese traditional buildings are made of wood materials. Wood members, especially columns, are prone to decay damage. A total of 13 partially-damaged wood columns repaired and strengthened with new wood blocks parallel to the wood grains and wrapped with CFRP stripes were experimentally studied. The ultimate compressive strength of partially-damaged wood columns is significant decreased in comparison with the control specimen, the range of decrease is larger than the loss of the cross-section, and the failure mode would change from central axial compression to eccentric compression. After replacing the damaged area with wood blocks parallel to the wood grains and wrapping up with CFRP stripes, both the load-bearing capacity and the ductility would be restored. If the wood blocks were misplaced perpendicularly to the wood grains, the load-bearing capacity would obviously decrease. It is found that combination of new wood blocks parallel to the wood grains and CFRP stripes is effective for repairing and strengthening partially-damaged wood columns.
Keywords:? wood column；CFRP；repair and strengthen；damage；load-bearing capacity；ductility
E-mail: qingfengxu@yahoo.com.cn

循环荷载作用下钢筋混凝土框格单元结构受力机理试验研究

喻　磊　张　荫　姚谦峰
（西安建筑科技大学，陕西西安710055）

摘要：为研究密肋复合墙板内钢筋混凝土框格单元结构的力学性能退化机理，对3个不同相对刚度比的框格单元及3个空框格结构进行了1/2比例模型循环加载试验。分析钢筋混凝土框格单元结构的破坏发展过程，探讨了外围框格构件对结构承载能力与变形能力的影响。研究结果表明框格单元结构的破坏顺序与结构相对刚度有关。随着结构相对强度的变化，框内填充砌体表现出不同的破坏模式。压缩变形越大，框格单元结构变形滞后现象越明显。界面缝隙对框格单元结构的初始刚度影响显著，但对峰值承载能力影响较小。经多次加卸载循环后，框格单元结构的峰值承载能力仍远高于对应的空框格结构。当外围框格构件与填充砌体在刚度与强度两方面均匹配时，填充砌体刚度退化较慢。
关键词：钢筋混凝土；密肋复合墙板；变形滞后；界面缝隙；刚度退化

An experimental study on the load-bearing mechanism of elemental
reinforced concrete frames under cyclic load

Yu Lei? Zhang Yin?? Yao Qianfeng
（Xi’an University of Architecture & Technology, Xi’an710055, China）

Abstract: In order to investigate the degradation mechanism of the mechanical property of elemental reinforced concrete frames in multi-ribbed walls， three elemental reinforced concrete frames with different relative stiffness and three identical frames without infill were tested under cyclic load. All the specimens are in the scale of 1:2. The damage process of the specimens is analyzed， and the effects of the peripheral frame members on the load-resisting capacity and deformation behavior are discussed. It is revealed that the cracking sequence of the elemental reinforced concrete frames is closely related to the structural relative stiffness. The failure modes of the infill vary with the structural relative strength. With increase in compressive deformation， the deformation hysteresis becomes more evident. The influence of the interface gap between the infill and the peripheral frame members on the initial stiffness of the elemental reinforced concrete frames is significant， whereas the influence on the peak load-resisting capacity of elemental reinforced concrete frames is relatively small. After several loading loops the load-resisting capacity of the elemental reinforced concrete frames is greater than that of the frames without infill. When peripheral frame members match the infill in terms of both stiffness and strength， degradation of the stiffness of the infill is slow.
Keywords: reinforced concrete; multi-ribbed walls; deformation hysteresis; interface gap; stiffness degradation
E-mail: yu@xauat.edu.cn

高轴压比PVA纤维超高强混凝土短柱延性的试验研究

姜　睿^1,2　徐世烺²　贾金青²
（1.鲁东大学，山东烟台264025；2.大连理工大学，辽宁大连116024）

摘要：试验旨在研究在较高轴压比条件下，高弹模PVA纤维对超高强混凝土短柱抗震延性的改善作用。制作剪跨比为2.0的短柱试件，强度为103.6～112.1MPa，PVA纤维的体积含纤率分别为0.17%、0.33%、0.5%。采用简支梁加载图式进行低周反复荷载试验。观测试件在荷载作用下的开裂和破坏的发展过程，研究不同PVA纤维含量短柱的破坏形态、滞回特性，得到短柱的开裂荷载和峰值荷载。试验结果表明：未掺PVA纤维的试件，在高轴压作用下，发生脆性特征明显的剪切破坏，延性很差。随着PVA纤维含量的增加，试件的破坏形态向具有一定延性特征的弯剪破坏转变，并且开裂荷载和峰值荷载得到大大提高，提高的幅度分别为12.8%~31.1%、13.2%~29.9%；同时抗震延性得到大大改善，位移延性和极限弹塑性位移角分别增加了19.5%~33.6%、42.3%~53.8%。最后给出满足一定位移延性和极限弹塑性位移角的抗震设计要求的最小PVA纤维体积含纤率的建议值。
关键词：超高强混凝土短柱；延性；抗震性能；高弹模PVA纤维

An experimental study on the seismic ductility of PVA fiber super-high-strength concrete columns with high axial load ratios

Jiang Rui^1,2? Xu Shilang²? Jia Jinqing²
(1.Ludong University, Yantai 264025, China;
2.Dalian University of Technology, Dalian 116024, China)

Abstract：The primary objective is to study the effect of high-modulus PVA fibers on improving the seismic performance of super-high-strength concrete short columns with high axial pressure ratio. Specimens with the concrete strength ranging from 103.6 to 112.1Mpa and a shear span ratio of 2.0 were manufactured. The high modulus PVA fibers were added with the volume fractions of 0.17%, 0.33% and 0.5%. The specimens were subjected to low cyclic reversed lateral load to simulating simple supported beams. The cracking and damage process of the specimens were studied, the failure patterns and hysteretic behavior of short column specimens with different PVA fiber volume fractions analyzed, and the initial cracking load and the maximum load for the short columns determined. The test results indicate: under high axial load, the specimen without PVA fibers exhibited brittle shear failure with poor ductility. However, with increase in the fiber volume fractions, flexure-shear failures with certain ductile characteristics were observed, and both the crack load and the maximum load greatly enhanced greatly by 12.8%~31.1% and 13.2%~29.9%, respectively. The seismic ductility was also improved greatly, with the displacement ductility and the drift ratio of the specimens being improved by 12.8%~31.1% and 13.2%~29.9%, respectively. Minimum PVA fiber volume fractions that can satisfy certain seismic requirement on displacement ductility and drift ratio were put forward.
Keywords：super-high-strength concrete short column; ductility; seismic performance; high-modulus PVA fiber
E-mail：Jiangrui72@yahoo.com.cn

上海长江大桥车桥系统节段模型涡激共振试验研究

周　立　葛耀君
（同济大学土木工程防灾国家重点实验室，上海200092）

摘要：涡激共振通常都在低风速发生，且涡激共振对断面形式的微小变化很敏感，因此有必要研究车辆对车桥系统涡激共振性能的影响。以上海长江大桥为背景，在同济大学土木工程防灾国家重点实验室TJ-1边界层风洞中进行了1∶60缩尺模型试验，开展了桥面无车状态、桥面有车状态下的两种断面形式以及0°、+3°和-3°三种风攻角共6个试验工况节段模型涡激共振试验研究，并将模型试验结果经过振型修正换算到实桥。试验结果表明：桥面有车状态下的竖弯涡振和扭转涡振中分别伴有相同频率的扭转振动和竖弯振动；桥面有车状态的竖弯涡振和扭转涡振幅值明显比桥面无车状态大；桥面有车状态下的涡振锁定风速区间比桥面无车状态下提前。可见车辆明显改变了主梁的气动外形，且无论从振幅还是振动形态方面考虑，车辆对车桥系统的涡激共振影响是不可忽视的。
关键词：车桥系统；节段模型；涡激共振；风洞试验；振型修正

Sectional model test study on vortex-excited resonance of vehicle-bridge system of Shanghai Bridge over Yangtse River

Zhou Li　Ge Yaojun
（State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University,
Shanghai 200092, China）

Abstract: It is necessary to study how vehicles influence the vortex-excited resonance of vehicle-bridge systems， because lock-in wind speed is low and vortex-excited resonance is sensitive to any change of main girder sections. Based on the Shanghai Bridge over Yangtse River， the vortex-excited resonance of a 1:60 scale sectional model was tested in a TJ-1 wind tunnel， without or with vehicles at the attack angle of 0（， +3（ and -3（， respectively. The conversion relationships between the resonant amplitudes of the sectional model and that of the prototype bridge were also established by mode shape correction. The result indicates that: a） for the bridge with vehicles， the vertical vortex-excited resonance is accompanied by torsion vibration with the same frequency， and vice versa， b） the amplitude of vortex-excited resonance of the bridge with vehicles is much larger than that of the bridge without vehicles， and c） the lock-in wind speed of the vortex-excited resonance becomes smaller due to the disturbance of vehicles. It is obvious that vehicles bring about changes in the aerodynamic shape of the main girder. Therefore， the influence of vehicles on vortex-excited resonance performance of vehicle-bridge systems， in terms of both amplitude and mode， should not be ignored.
Keywords: vehicle-bridge system；sectional model；vortex-excited resonance；wind tunnel test；mode shape correction
E-mail: zhouli333@163.com

矩形闭合墙桥梁基础墙-土-承台相互作用研究

文　华¹　程谦恭¹ 孟凡超²　陈晓东²
（1. 西南交通大学，四川成都610031；2. 中交公路规划设计院，北京100010）

摘要：矩形闭合地下连续墙基础是一种新型的桥梁基础。通过室内模型试验，对闭合墙基础墙-土-承台相互作用进行系统的研究。试验研究表明：闭合墙基础承台土反力分布的总体特征是承台下土芯的角点处最大，边缘处次之，中心区最小。在一定范围内，承台下土芯截面积越大，承台土反力分布越趋于均匀化。承台对上部墙段的内摩阻力存在“削弱效应”，而对下部墙段的内摩阻力则有一定的“增强效应”，承台对墙端阻力也有一定的“增强效应”。承台土反力的荷载分担比约为10％～20％，若在闭合墙的竖向承载力计算方法中，不考虑承台的作用，忽略承台土反力，是不合理的。模型试验和分析结果为矩形闭合地下连续墙基础的设计计算提供了重要依据。
关键词：地下连续墙；桥梁基础；低承台；相互作用

Diaphragm wall-soil-cap interaction in rectangular-closed-diaphragm-wall bridge foundations

Wen Hua¹　 Cheng Qiangong¹　Meng Fanchao²　Chen Xiaodong²
（1. Southwest Jiaotong University， Chengdu 610031， China;
2. China Highway Planning and Design Institute， Beijing 100010， China）

Abstract: Rectangular-closed-diaphragm-wall foundation is a new type of bridge foundation. Diaphragm wall-soil-cap interaction was studied through a model test. It was observed that the distribution of soil resistance under the cap is not homogeneous. Soil resistance in the corner under the cap is larger than that in the border, and soil resistance in the center is the smallest. The distribution of soil resistance under the cap will be more uniform, if sectional area of soil core is enlarged to a certain extent. Due to the existence of the cap, there is "weakening effect" in inner shaft resistance of the upper wall segments, and there is “enhancement effect” in the lower wall segments and in the toe resistance. Load shearing percentage of soil resistance under the cap is 10%~20%. It is unreasonable to ignore the effects of the cap and the soil resistance under the cap in bearing capacity calculations.
Keywords: diaphragm wall; bridge foundation; low cap; interaction
E-mail: wenhua189@163.com

FRP土钉主要性能的试验研究

黄生文¹　邱贤辉¹　何唯平²　刘廷望¹
（1长沙理工大学，湖南长沙410076；2 深圳海川工程科技有限公司，广东深圳518004）

摘要：介绍一种新型FRP土钉的主要特点。对FRP筋体抗拉强度和黏结强度及FRP土钉的承载力分别进行室内试验和现场拉拔试验研究，描述并分析其破坏特征。试验表明：FRP筋体抗拉强度高达550 MPa，在筋材设计时，可采用修正的混合定律公式进行预测，FRP筋在抗拉强度试验中表现为脆性破坏，树脂基体破碎先于纤维拉断，断裂截面呈参差不齐的毛刷状；FRP筋体与水泥砂浆的黏结强度取决于砂浆体的抗剪强度，黏结应力沿杆长非均匀分布，且FRP筋的最大黏结应力较钢筋更为集中；FRP土钉的变形主要是弹性变形，对于较短的FRP土钉，其承载力大小取决于土钉表面与土体间的抗剪强度，其极限抗拔承载力高于同直径的HRB335钢筋的屈服抗拉强度10％以上，满足工程应用的需要。故FRP土钉可广泛应用于基坑和边坡支护，特别是污染土、盐渍土等腐蚀环境下的土钉支护工程。
关键词： FRP；土钉；材料试验；拉拔试验；破坏特征

An experimental study on the performance of FRP soil nails

Huang Shengwen¹?? Qiu Xianhui¹?? He Weiping²?? Liu Tingwang¹
(1. Changsha University of Science and Technology, Changsha 410076, China;
2.Shenzhen Oceanpower Engineering Technology Co.,Ltd., Shenzhen 518004,China)

Abstract：The main characteristics of a new type of FRP soil nail are introduced. Laboratory studies on the tensile strength and the grouted bonding strength of the FRP rod and in-situ tests on the pull-out bearing capacity of FRP soil nails are carried out. Their failure features are described and analyzed. The test results indicate that the tensile strength of FRP rod, as high as 550MPa, can be evaluated by using a formula of modified mixture rule.? The rod failure appears brittle, the fibers in the rod are ruptured after the resin matrix around the fibers cracked, and the fracture assumes an irregular brush shape.? The bond strength between FRP rod and mortar is determined by the shear strength of mortar, the distribution of bond stress along FRP rod is non-uniform, and the maximum bond stress is more centralized than that of steel rod.? The deformation of FRP soil nails is basically elastic, the ultimate anti-pull out bearing capacity is controlled by the shear resistance between soil nail surface and soil mass for the shorter nails in the in-situ test, and the value is 10% higher than the yielding tensile resistance of HRB335 steel rod of the same diameter. Therefore, FRP soil nails can be widely applied in the retaining structures of foundation excavation and the reinforcement of slopes, especially under corrosive environments such as polluted and saline soils.
Keywords：FRP; soil nail; material test; pull-out test; failure characteristics
E-mail：hswcslg@yahoo.com.cn

地下工程抬升注浆设计方法及其抬升效果预测研究

唐智伟　赵成刚　张顶立
（北京交通大学，北京100044 ）

摘要：以北京地铁五号线崇文门地铁车站下穿既有线抬升注浆工程为研究对象，结合监测数据与三维有限差方法分析新建车站开挖引起既有线沉降的特征，以此为依据进行抬升注浆设计。通过在“注浆单元”上施加膨胀压力模拟注浆抬升既有结构的效果并与实测数据做对比，验证了施加膨胀压力模拟抬升注浆的正确性和有效性，为今后类似工程的设计提供了预测抬升效果的方法。在此基础上进一步研究得出止浆墙能有效限制土体侧向膨胀，提高抬升效果的结论。
关键词：抬升注浆；既有线；止浆墙；数值模拟

Design of displacement grouting and prediction of the effect for
construction of underground structures

Tang Zhiwei Zhao Chenggang Zhang Dingli
（Beijing Jiaotong University，Beijing100044, China）

Abstract: The project was to artificially raise an existing tunnel by grouting for the construction of the Chongwenmen subway station of Beijing Metro Line 5. In situ measured data and 3-D finite difference analysis were employed to analyze the settlement features of the existing tunnel caused by excavation, and displacement grouting was designed in accordance with the settlement features. In the numerical simulations, expanding pressure was applied to the grouting elements to simulate the heaving effect of grouting on the existing tunnel. Comparing with the measured data, the numerical method is proved to be suitable, and can be used to predict the effect of displacement grouting for similar projects. It is concluded that the grouting-proof curtain was effective in limiting lateral soil expansion and in enhancing the effect of displacement grouting.
Keywords: displacement grouting; existing tunnel; grouting-proof curtain; numerical modeling
E-mail: micktzw@tom.com

隧道围岩压力的应力分析方法

林乐彬¹　刘寒冰¹　刘　辉²
（1.吉林大学，吉林长春130022；2.长沙理工大学岩土工程研究所，湖南长沙410076）

摘要：围岩压力值是进行隧道设计和稳定性研究的重要依据，一般求解围岩压力常采取经验简化方法，如普氏计算法、太沙基计算方法等。这些经验方法简单实用，但求得的围岩压力值没有考虑隧道断面的形状影响和局部的压力变化，更无法考虑隧道围岩复杂的地质条件和地形地表条件，在隧道结构设计中有一定的局限性。有限元法在求解非线性问题和复杂边界问题方面有很好的效用，目前是岩土工程采用最为广泛的数值分析方法。从应力分析的角度，通过应用有限元软件对湖南湘西某隧道进行应力分析，得到隧道围岩压力的规律，给出应力分布图和包括顶压和侧压的围岩压力图，进而分析该隧道的稳定性。
关键词：应力分析；有限元法；隧道；围岩压力

Stress analysis method for pressure of surrounding rocks on tunnels

Lin Lebin¹　Liu Hanbing¹　Liu Hui²
（1.Jilin University，Changchun130022，China；2.Institute of Geotechnical Engineering，Changsha University of Science and Technology，ChangSha 410076，China）

Abstract: Surrounding rock pressure on tunnels is a key parameter for tunnel design and stability analysis. It is commonplace that the rock pressure is calculated by using some classical simplified methods， such as the Terzaghi theory and Promojiyfakonov theory. Although practical， these simplified methods are limited by its incapability of considering the shape of the tunnel cross-section， the local stress difference， the geological condition， the structure of the surrounding rocks， and the terrain topography. In this paper， the basic theory of FEM is introduced together with the adopted software of Geocad-SAFE. Numerical stress analysis is carried out for a tunnel located in west Hunan Province. The stress distribution around the tunnel is obtained and the stability of the surrounding rocks is studied.
Keywords: stress analysis；finite element method；tunnel；surrounding rock mass stress
E-mail: linlb@cein.gov.cn

混合交通网络设计的双层模型及遗传算法求解

聂　伟¹　邵春福²　杨励雅²　牛学军2
（1.深圳大学，广东深圳518060；2.北京交通大学，北京100044）

摘要：根据混合交通网络设计问题的特点，利用双层规划模型和遗传算法对该问题进行求解。对交通网络中的路段进行分类，通过限定决策变量的取值范围，将混合交通网络离散化。建立混合交通网络设计的双层模型。其中，上层模型以方案总投资额最小为目标函数，以路段负荷度和可行域为约束条件；下层模型为交通流分配的用户均衡模型。根据所建模型的离散特性，研究其遗传算法解法，并给出算法的具体实现步骤。以一个抽象的交通网络为例，给定网络中的路段属性、OD交通量等参数，利用MATLAB软件对模型编程求解，能够获得满意的交通网络设计方案，表明双层模型和遗传算法是一种研究混合交通网络设计问题的有效方法。最后，对该模型存在的不足及改进方向进行了探讨。
关键词：混合交通网络设计；双层优化模型；遗传算法；交通流分配

Bi-level programming model for mixed transportation network design and
genetic solution algorithm

Nie Wei¹　Shao Chunfu²　Yang Liya²　Niu Xuejun²
（1.Shenzhen University, Shenzhen 518060,China;
2. Beijing Jiaotong University，Beijing100044，China）

Abstract: A bi-level programming model and a genetic algorithm are used to solve mixed transportation network design problems. To make the mixed network discrete, the road is classified and the range of decision-making variables restricted. A bi-level programming model for mixed transportation network design is presented based on previous research results. In the upper level, minimization of total investment is used as the objective, and feasible region and degree of traffic congestion of the road in the network as the constraint conditions. The user equilibrium assignment is chosen as the lower level programming model. Genetic algorithm is used to solve the bi-level model based on the discrete attribute of the model, and the specific measures of the algorithm are also presented. Taking a simplified transportation network as example and setting up parameters such as OD traffic flow, road attributes, etc., a relatively satisfactory network design scheme is obtained by programming the bi-level model with MATLAB. The results indicate that the bi-level programming model and the genetic algorithm are effective for mixed transportation network design. The shortcomings and the improvement directions of the model are discussed.
Keywords: mixed transportation network design; bi-level programming problem; GA; traffic assignment
E-mail: niewei118@126.com

基于二维染色体编码的集装箱海运网络免疫算法优化模型

黄　俊　宋向群　郭子坚
（大连理工大学，辽宁大连116023）

摘要：集装箱船舶大型化趋势的日益显著，为船公司和港口运营商带来巨大规模经济效益。要实现这种规模经济，必须合理选择集装箱船舶运营航线及船型尺度，优化整个运输网络。针对区域性集装箱港口群的网络径流优化问题，引入基于二维染色体编码的免疫算法。二维染色体编码能够准确描述集装箱海运网络的结构特点，简化网络建模过程，从而保证基于二维染色体编码的免疫算法对集装箱海运网络优化问题具有良好的适应性。算法通过模拟免疫系统的功能构建优化模型，避免经典算法组合寻优过程中难以克服的组合爆炸问题，从而快速、有效地使运输网络总成本收敛到最小，为集装箱港口的运营管理，特别是航线和船型选择提供充实的理论依据。试验结果同时表明，大型集装箱船舶比小型船舶更具有成本优势，规模经济效益促使集装箱船型尺度进一步增大。
关键词：免疫算法；二维染色体编码；港口；集装箱运输网络

An IA optimization model of container marine transport
based on two-dimensional chromosome encoding

Huang Jun　Song Xiangqun　Guo Zijian
（Dalian University of Technology，School of Civil and Hydraulic Engineering，
Dalian116023, China）

Abstract：It has become apparent that the use of mega-container ships for maritime transport can bring considerable economical benefits to both carriers and shippers. In order to make this into a reality, one may have to optimize the maritime transport network, thus to maximize the scale of economy. The action must be complemented with a reasonable selection of container type and programming of sea route. The present paper deals with the optimization work of marine transport network for a group of container seaports by a heuristic method Immune Algorithm (IA) on the basis of two-dimensional chromosome encoding. As it is known, the two-dimensional chromosome encoding could accurately express the characteristic of the transport network; IA on the basis of it can resolve the problem properly. The simulation results indicate that IA can avoid an insurmountable combinational explosion flaw by simulating the behavior of natural immune system, and account for the aforementioned uptrend. Hence, a reliable method is provided for the vessel and port operators to rationally plan the container maritime transport system.
Keywords：Immune Algorithm；two-dimensional chromosome encoding；port and harbors；container marine transport network
E-mail：emeihj@gmail.com

基于均衡价格形成机制的住宅价格变化特征研究

张　红　翁少群
（清华大学，北京100084）

摘要：依据供求关系原理和住宅价格变化特征模型，探讨住宅均衡价格的形成机制与住宅实际价格的变化机理。利用我国35个大中城市2000~2004年的经济统计指标和住宅市场数据，识别出住宅均衡价格；并将实际价格变化分解成均衡价格变化、实际价格的均值回复和趋势性运动等三个组成部分，重点研究住宅实际价格与均衡价格之间的关系。研究表明：我国住宅市场存在由供求基础决定的均衡价格，城镇家庭人均可支配收入、个人住房抵押贷款利率水平、城镇人均居住面积、非农人口数等需求因素，以及供给成本、城市化水平和城市建成区面积等供给因素对住宅均衡价格存在显著影响；住宅实际价格的变化受到均衡价格变化的显著影响；住宅实际价格可通过自我调整回复到均衡价格水平，并存在缓慢上涨的趋势。
关键词：住宅价格；均衡；机制；变化；特征

Analysis of housing price fluctuations based on the
formation mechanism of equilibrium price

Zhang Hong　Weng Shaoqun
（Tsinghua University，Beijing100084，China ）

Abstract: In order to find out the mechanisms of housing price formation and fluctuation, the equilibrium housing price is identified by using the classic supply-demand theory, and an analysis model of price fluctuation proposed. Using a set of data on the economic statistics and housing markets of 35 metro areas in China from 2000 to 2004, equilibrium housing prices are proved and calculated; the fluctuation of actual housing prices is decomposed into the influences of equilibrium price, mean reversion and the autocorrelation. The results indicate that equilibrium housing prices as determined by the basic economy foundation exist in China. Demand factors, such as per capita disposable personal income, mortgage interest rate, per capita dwelling space, non-agriculture population, together with the supply factors, such as land cost index, and construction cost, urbanization and urban built-up area, all have significant influences on the equilibrium housing prices. Actual housing prices are greatly influenced by the fluctuation of the equilibrium housing prices and could revert to the equilibrium with the process of self-adjustment. The study also shows that housing prices in China would be continuing to rise in the future.
Keywords: housing price; equilibrium; mechanism; fluctuation; characteristics
E-mail: zhannie@tsinghua.edu.cn

基于网络协同的建设项目价值管理系统

郭建锋¹ 　张建平¹　沈岐平²
（1．清华大学，北京100084；2. 香港理工大学，香港）

A CSCW-based value management system for construction projects

Guo Jianfeng¹　Zhang Jianping¹　Shen Qiping²
（1.Tsinghua University， Beijing100084，China;
2.Hong Kong Polytechnic University，HK, China）

Abstract: Value Management (VM) is an effective approach to reduce the cost and improve the process effectiveness and efficiency of construction projects. However, many problems such as lack of people's awareness, lack of implementation guideline and lack of promotion policy have greatly limited the applications of VM in the Chinese construction industry as well as the output quality. The Interactive Value Management System (IVMS) that is developed based on the practices of VM applications in Hong Kong's construction industry cannot be effectively adopted in mainland China, due to the differences in job plans, approaches and the fact that IVMS does not support remote CSCW. Based on the VM practices in the Chinese construction industry, a CSCW-based value management system named IVMS-CN is proposed. IVMS-CN is composed of a network-based communication platform, a CSCW platform and a management platform. It aims to provide a remote collaborative environment and a group decision support platform for VM members so that they can take part in VM studies in different places. IVMS-CN can also facilitate the communication and information sharing between VM members, reduce process losses and improve process gains so that the qualities and effectiveness of VM practices in the Chinese construction industry can be improved.
Keywords: value management (VM); group decision support system; network; computer supported cooperative work (CSCW); construction project
E-mail: guojianfeng98@mails.thu.edu.cn