FRP约束圆柱混凝土受压应力－应变关系模型

刘明学 钱稼茹
（清华大学，北京100084）

摘要：为建立纤维增强复合材料（FRP）约束圆柱混凝土受压应力－应变关系模型，分析了国内外305个轴心受压FRP约束混凝土圆柱试件的试验结果。分析表明，纤维特征值、FRP层合结构和加载方式是影响FRP约束圆柱混凝土受压应力－应变关系的3个主要因素。通过分析试验结果和已有的模型，提出了一个考虑上述3个因素的改进的FRP约束圆柱混凝土受压应力－应变关系模型，该模型包括强化型和软化型两种类型。比较表明，该模型与试验结果的符合程度好于已有模型。
关键词：纤维特征值；FRP层合结构；加载方式；FRP约束混凝土圆柱；混凝土应力－应变关系模型

Compressive stress-strain model for concrete of FRP confined cylinders
Liu Mingxue Qian Jiaru

(Tsinghua University, Beijing 100084, China)

Abstract: To develop a compressive stress-strain model for fiber reinforced polymer (FRP) confined concrete, the test results of 305 axially loaded FRP confined concrete cylinder (FCC) specimens are analyzed. The analytic results indicate that the fiber characteristic value, the FRP laminate structure and the loading method are the three major factors that influence the compressive stress-strain relationships of concrete of the FCCs. By analyzing the 305 test results and the existing models, an improved compressive stress-strain model for concrete of the FCCs, with the three factors taken into consideration, is proposed. The model includes work hardening and softening. Comparing with the test results, the agreement of the proposed model is better than that of the existing models.
Keywords: fiber characteristic value; FRP laminate structure; loading method; FRP confined concrete cylinder; concrete stress-strain model
E-mail: qianjr@mail.tsinghua.edu.cn

FRP约束混凝土圆柱有软化段时的应力－应变关系研究

吴 刚1 吴智深1，2 吕志涛1
（1. 东南大学,江苏南京210096 2. 日本茨城大学，日立316-8511）

摘要：试验研究了不同数量、不同类型（高强度、高弹模、高延性）FRP约束混凝土圆柱的应力－应变关系，发现其应力－应变关系曲线可能有软化段也可能没有软化段。指出FRP约束混凝土圆柱的轴向最大应力主要与侧向约束强度或侧向约束刚度有关，而轴向极限应变除了与该两个参数有关外，还与FRP的轴向极限拉应变有关。基于试验及搜集到的数据，提出判断FRP约束混凝土圆柱有无软化段的侧向约束强度与混凝土强度比界限值。基于对FRP侧向约束刚度和强度、FRP轴向极限拉应变、混凝土强度及弹性模量等参数的分析，提出了FRP约束混凝土圆柱有软化段时的峰值应力、峰值应变、极限应力及极限应变计算公式。最后，建议了两个确定FRP约束混凝土圆柱有软化段时的应力－应变关系模型。与大量试验数据的比较表明，本文建议的公式和模型与试验结果均符合较好。
关键词：纤维增强聚合物(FRP)；混凝土圆柱；约束；软化；应力－应变关系

Study of the stress-strain relationship of FRP-confined circular concrete
column with a strain-softening response

Wu Gang1 Wu Zhishen1，2 Lü Zhitao1
（1. Southeast University，Nanjing 210096, China；
2. Ibaraki University, Hitachi 316-8511, Japan）

Abstract: The performances of circular concrete columns confined with FRP of various volumetric ratios and three different types of FRPs, including high strength FRP, high modulus of elasticity FRP and high ductility FRP, were tested. The FRP-confined circular concrete columns may or may not exhibit strain-softening. The maximum stress of FRP-confined concrete mainly depends on the confinement strength or the confinement modulus of FRP, while the axial ultimate strain of FRP-confined concrete is related not only to these two parameters but also to the ultimate tensile strain of FRP. Boundary values of the confinement ratio are suggested for determining the stress-strain curves of FRP-confined circular concrete columns with or without strain-softening. Based on the discussions on the effects of confinement strength and confinement modulus of FRP, the ultimate tensile strain of FRP, the strength and the modulus of elasticity of concrete, two stress-strain models as well as formulations for predicting the peak stress and the corresponding strain, the ultimate stress and the ultimate strain of FRP-confined circular concrete columns with strain-softening are proposed. The formulations and models demonstrate good agreement with experimental results from the present and previous studies.
Keywords: fiber reinforced polymer(FRP) ; circular concrete columns; confinement; softening; stress-strain relationship
E-mail: g.wu@seu.edu.cn

大型预制预应力混凝土空间结构试验研究

薛伟辰1 陈以一1 姜东升1 徐壮涛1 林颖儒2
（1.同济大学，上海 200092；2.上海建筑设计研究院有限公司，上海 200041）

摘要：以上海旗忠网球中心预制预应力混凝土看台结构为原型，设计了1∶15缩尺模型，在国内首次开展了大型预制预应力混凝土空间结构单调静力全过程试验研究与非线性有限元分析，重点研究了结构的破坏形态、破坏机制以及裂缝发展、预应力筋应力增量、钢拉杆应力和截面曲率等的变化规律。研究表明：结构由于径向主梁根部混凝土的压碎而导致破坏；在设计荷载作用下结构基本处于弹性工作状态且整体性能良好；裂缝最早出现在相邻预制斜梁的环梁一之间的拼缝处；在加载前期64根预制斜梁在预应力的作用下能够较好地实现共同工作，而在加载后期各预制斜梁则形成局部受力机制单独承载，并最终在径向主梁根部发生压弯破坏；结构有较大的安全储备和变形能力，结构整体位移延性系数达到了2.04。本文研究成果可为大型预制预应力混凝土空间结构的推广和应用提供试验与理论依据。
关键词：预制预应力混凝土；空间结构；单调静力试验；非线性有限元；破坏机制；位移延性

Experimental study on large precast prestressed concrete spatial structures

Xue Weichen1 Chen Yiyi1 Jiang Dongsheng1 Xu Zhuangtao1 Lin Yingru2
(1.Tongji University，Shanghai 200092;
2.Institute of Architectural Design & Research,Shanghai 200041）

Abstract: Monotonic static test and nonlinear finite element analysis are conducted on a 1∶15 scaled model of a large precast prestressed concrete spatial structure in China to investigate the failure mode, failure mechanism, variation of crack propagation, the stress increment of prestressed tendons and steel rebars and the section curvatures. Experimental results indicate that the structure fails when the concrete at roots of radial girders crushes and the structure is basically in the elastic range under the design loads. Cracks initiate at the joints of the precast oblique beams and the circular beams. All 64 precast oblique beams work concertedly under the applied prestressing at the early stage of loading, and work separately at the later stage of loading. The structure finally fails in compressive bending at the roots of the radial girders. The structure behaves with a rather sufficient safety margin and a deformation capacity with a displacement ductility coefficient of about 2.04.
Keywords: precast prestressed concrete; space structure; monotonic static test; nonlinear finite element; failure mechanism; displacement ductility
E-mail: xuewc@mail.tongji.edu.cn

预应力钢纤维混凝土板弯曲疲劳弹性模量试验研究

侯 杰1 程赫明1 王时越1 田 芳2
（1.昆明理工大学，云南昆明650093；2.衢州学院，浙江衢州324000）

摘要：对三种不同钢纤维掺量（0%、1%、2%）的预应力钢纤维混凝土板在不同应力水平（0.80、0.85）下的疲劳弹性模量衰减规律进行研究，得到了预应力钢纤维混凝土板跨中下表面弹性模量衰减曲线以及同钢纤维掺量、同应力水平的跨中上表面弹性模量衰减曲线。揭示了预应力钢纤维混凝土板的弹性模量在弯曲疲劳过程中呈现三阶段衰减并且衰减曲线在第二阶段基本呈线性，当板发生疲劳破坏时其弹性模量衰减至初始弹性模量的59.9%左右的规律。在此基础上根据Miner累积损伤原理建立了疲劳寿命预测模型并提出了采用微损试验来预测疲劳寿命的方法，用该方法预测的疲劳寿命与实测寿命在三倍离散范围内。
关键词：预应力钢纤维混凝土板；疲劳；弹性模量；疲劳寿命预测

Experimental study on the fatigue elastic modulus of
steel fiber reinforced prestressed concrete slabs

Hou Jie1 Cheng Heming1 Wang Shiyue1 Tian Fang 2
（1.Kunming University of Science and Technology, Kunming 650093, China;
2.Quzhou college, Quzhou 324000, China）

Abstract: The attenuation of elastic modulus of Steel Fiber Reinforced Prestressed Concrete Slabs (SFRPCS) with different steel fiber contents (0%、1%、2%) and under different stress levels (0.80、0.85) is investigated through flexural fatigue experiments. Three types of attenuation curves in the middle of slabs are obtained，and these curves reveal that the elastic modulus attenuation of SFRPCS could be divided into three stages during the fatigue process and the second stage is nearly linear. The elastic modulus is about 59.9 percent of its initial value when the SFRPCS fails．A model for fatigue-life prediction is proposed according to the Miner cumulative damage theory, and a method of micro-damage experiment is provided to predict the fatigue-life. The model predicted fatigue-life is within three times of the experimentally measured fatigue-life.
Keywords: steel fiber reinforced prestressed concrete slab； fatigue； elastic modulus； fatigue-life prediction
E-mail: houjie01107@163.com

单层柱面网壳在强震下的破坏机理研究

王晓可 范 峰 支旭东 沈世钊
(哈尔滨工业大学，黑龙江哈尔滨150090)

摘要：柱面网壳的结构形式、受力特性与其他网壳结构不同，造成其在强震下破坏机理的特殊性。采用基于结构响应的全过程分析方法，利用软件Abaqus，综合宏观、微观响应指标，对单层柱面网壳进行大规模的参数分析，探求其在强震下的破坏机理。通过典型算例的分析比较，确定了单层柱面网壳的破坏模式及其特征，总结了临界荷载的确定方法。在大量计算数据统计的基础上，提出了单层柱面网壳实用的动力破坏判别准则。单层柱面网壳在强震下可能出现的动力失稳破坏突然，破坏时塑性发展浅,结构刚度几乎没有削弱，结构位移小。单层柱面网壳在强震下强度破坏也可能出现，情况与前不同，其中强度破坏包括强度破坏Ⅰ和强度破坏Ⅱ，强度破坏Ⅱ有明显失稳现象而强度破坏Ⅰ没有。动力实用判别准则以最大节点位移和8p比例为参考指标，用来确定强度破坏Ⅰ和强度破坏Ⅱ极限荷载。对考虑损伤的柱壳破坏机理进行了初步探讨，损伤对不同的结构影响不同，给出了工程设计中损伤降低系数的建议值。
关键词：单层柱面网壳；强震作用；破坏机理；动力失稳；强度破坏

Failure mechanism of single-layer latticed cylindrical
shells subjected to strong earthquake

Wang Xiaoke Fan Feng Zhi Xudong Shen Shizhao
(Harbin Institute of Technology, Harbin 150090, China)

Abstract: The characteristics of latticed cylindrical shells are different from those of other latticed shells，which make some particularity on failure mechanism. Based on the structural response analysis method in Abaqus, considering multi-indexes responses from macroscopic and microscopic levels, a large number of parameter analyses for single-layer latticed cylindrical shells have been done, which can be used for exploring the failure mechanism under strong earthquakes. After the analysis of some typical cases the failure modes and some characteristics have been determined. According to a great number of analytical calculated data a practical dynamic failure criteria of single-layer latticed cylindrical shells is given. Under strong earthquakes, the dynamic instability of single-layer latticed cylindrical shells may appear suddenly, and when it happens, the plastic deformation is very limited, the structural stiffness is almost as same as before and the displacements are not considerable. The strength failure of single-layer latticed cylindrical shells may also happen. It seems quite different. The strength failure includes strength failure modeⅠ and strength failure modeⅡ. Strength failure modeⅡ has obvious similar phenomena as those in dynamic instability, while strength failure modeⅠhas not. Using maximum displacement and the ratio of whole-section yield elements (8p) as reference indexes the practical failure criteria can be used for determining the ultimate loads of strength failure modeⅠ and modeⅡ. In this paper the preliminary study on failure mechanism of damaged single-layer latticed cylindrical shells subjected to strong earthquake motion is also studied, a reduced damage coefficient for engineering design is given.
Keywords: single-layer latticed cylindrical shell; strong earthquake; failure mechanism; dynamic instability; strength failure
E-mail: gloria-w@163.com

索穹顶结构施工成形理论分析和试验研究

陈联盟1，2 董石麟2 袁行飞2
（1．温州大学，浙江温州 325035；2．浙江大学，浙江杭州 310027）

摘要：根据索穹顶结构由拉索和压杆组成的几何拓扑关系，提出一种新的施工成形方案——由外及里逐圈按阶段分批调节压杆长度到原长的成形方案；并采用抛物线单元建立已知原长的构件变形后节点坐标与构件内力之间的关系，在此基础上提出了一种基于动力松弛法、控制构件原长求解各阶段平衡态时杆件内力和节点坐标的理论分析方法；最后通过设计加工一直径为5 m的索穹顶模型试验对该施工成形方案的可行性及理论分析方法的正确性进行了模拟和验证。试验结果与理论计算值基本符合，表明基于动力松弛法、控制构件原长的找形分析方法是正确有效的、由外及里逐圈分批调节压杆长度到原长的施工成形方案是可行的。
关键词：索穹顶结构；施工方案；动力松弛法；原长；模型试验

Theoretical and experimental study on the construction of cable domes

Chen Lianmeng1,2 Dong Shilin2 Yuan Xingfei2
(1.Wenzhou University, Wenzhou 325035,China;
2. Zhejiang University, Hangzhou 310027,China )

Abstract: Based on the geometric topology of the structures composed of cables in tension and struts in compression, a new construction scheme is proposed for adjusting the length of the struts from the outer to the inner hoop. The relationship between the nodal coordinates and the internal forces of the elements of known original length is established, and a method is proposed to find the internal force of the elements and the nodal coordinates of the structures in equilibrium state by controlling the original length with the dynamic relaxation method. A cable dome model with a diameter of 5.0m is formulated to test this theory. The experimental results are mostly consistent with the theoretical ones, which indicate that the proposed form-finding method by controlling the original length with the dynamic relaxation method is accurate and effective and the proposed construction scheme is reasonable.
Keyword: cable-dome; construction scheme; dynamic relaxation method; original length; model experiment
E-mail: wzchenlm@sina.com

大跨屋盖结构风致抖振响应研究

顾 明 周晅毅 黄 鹏
（同济大学，上海200092）

摘要：建立基于非定常风荷载的大跨屋盖结构风致动力响应的试验和分析方法。该方法采用多通道测压系统扩大同步测压点的数目，更全面地获得屋盖表面风压的时空特性，为准确计算结构风致响应奠定了基础。在动力分析方法上应用CQC法计算屋盖结构的风振响应，考虑多模态及模态间的耦合影响，编制了结构风致动力效应计算程序SWDP。最后对上海铁路南站工程屋盖结构的抖振响应结果进行了计算和分析。结果表明，采用多通道测压系统可以有效地扩大同步测压点的数目；基于非定常风荷载的CQC方法是计算复杂大跨屋盖结构风振响应的有效方法；背景响应对于总响应的贡献通常是不可忽略的。
关键词：大跨屋盖结构；非定常气动力；多通道测压系统；CQC法；动力响应

A study on the wind-induced buffeting responses of large-span roof structures

Gu Ming Zhou Xuanyi Huang Peng
（Tongji University, Shanghai 200092, China）

Abstract: A systematic method is developed for test and analysis of the non-steady wind pressure distributions in wind tunnel test of wind-induced dynamic responses of large-span roof structures. The parallel tube-manifold system is applied to augment the number of simultaneous measuring points to ensure that the non-steady wind pressures on a large-span roof can be obtained simultaneously from the rigid model wind tunnel test. The wind-induced buffeting responses can be computed by using the mode-superposition method (Complete Quadratic Combination method), to take the modal coupling effects into account, and a corresponding computer code-SWDP is developed. The characteristics of the buffeting responses of the roof structure of the Shanghai South Railway Station are analyzed. The results indicate:(1)the parallel tube-manifold system can effectively extend the number of simultaneous measurement points of wind pressures,(2)the non-steady wind load-based CQC method can be effectively employed for computing the dynamic responses of large roof structures, and (3) the background components usually contribute significantly to the total buffeting responses.
Keywords: large-span roof structure; non-steady wind pressure; parallel tube-manifold system; complete quadratic combination method; dynamic response
E-mail: minggu@mail.tongji.edu.cn

非比例阻尼线性体系地震响应的部分平方组合(CPQC)法

俞瑞芳 周锡元
（北京工业大学工程抗震与结构诊治北京市重点实验室，北京100022）

摘要：对于非比例阻尼线性系统，当采用基于复振型的地震反应谱振型叠加方法，即复振型完全平方组合（CCQC）方法进行动力反应分析时计算工作量较大。为此，通过分析不同振型之间的位移、速度、位移－速度相关系数随频率比和阻尼比的变化规律，给出了复振型平方和开方（CSRSS）组合方法的适用范围。同时通过分析指出在CCQC法中只需要考虑邻近振型的相关性，因此建议了一种介于CCQC法和CSRSS法之间的考虑部分相关性的复振型平方组合方法，称之为简化的CCQC法或复振型部分平方组合 (CPQC)方法, 用以提高计算效率。通过实例分析验证了所建议方法的适用范围、计算精度和效率。由于比例阻尼系统的地震反应谱振型组合方法是文中所述一般方法的特殊情况，因此本文提出的简化分析方法对比例阻尼系统也同样是适用的, 并可以称为部分平方组合 (PQC)方法。
关键词：振型组合；非比例阻尼；复完全平方组合法； 复振型部分平方组合方法；部分平方组合方法

A complex partial quadratic combination (CPQC) method for
seismic responses of non-classically damped linear system

Yu Ruifang Zhou Xiyuan
（Beijing Key Laboratory of Earthquake Engineering and Structural Retrofit,
Beijing University of Technology, Beijing, 100022）

Abstract: For non-classically damped linear systems, when the complex mode superposition method based on seismic response spectrum, i.e. the complex complete quadratic combination (CCQC) formula, is used for seismic response analysis, the amount of calculation is fairly large. Hence, the applicability of the CSRSS (complex square root of the sum of squares) method is provided for studying the variations of the modal displacement, velocity, displacement-velocity correlation coefficients along with the ratios of different frequencies and damping. Based on these analyses, a simplified method, which only considers the contributions from relatively adjacent modes in CCQC method and is named as simplified CCQC or complex partial quadratic combination (CPQC) method, is proposed for reducing computational time. A numerical example is presented to analyze the applicability, computational accuracy and efficiency. The proposed simplified method is useful for classically damped linear systems as well, and may also be named as a partial quadratic combination (PQC) method.
Keywords: mode superposition; non-classical damping; Complex Complete Quadratic Combination (CCQC) Method; Complex Partial Quadratic Combination (CPQC) Method; Partial Quadratic Combination (PQC) Method
E-mail: yuruifang@emails.bjut.edu.cn

各种级配大坝混凝土双K断裂参数试验研究
——兼对《水工混凝土断裂试验规程》制定的建议

徐世烺1 周厚贵2 高洪波1 赵守阳2
（1.大连理工大学海岸和近海工程国家重点实验室，辽宁大连116024；
2.中国葛洲坝集团公司，湖北宜昌443002）

摘要：为配合水工混凝土断裂试验规程在我国的制定，提供更充足的基础数据，受规程编制组委托，进行了最大尺寸为S×D×B=2200 mm×550 mm×240 mm的三点弯曲梁试件和最大尺寸为2H×D×B=1200 mm×1200 mm×250 mm的楔入劈拉试件共140个试件的断裂试验。通过电阻应变片，测得不同布置测点荷载应变变化曲线，由此确定了不同级配及湿筛法大坝混凝土实测的起裂荷载和失稳荷载，计算了双K断裂韧度参数，讨论分析了双K断裂参数的尺寸效应和形状效应。结果表明：电阻应变片法测定起裂荷载的方法可行，Pini/Pmax=0.6~0.85；三点弯曲梁法所得混凝土双K断裂韧度值无明显的尺寸效应；楔入劈拉试件由于竖向加载荷载PV引起附加力矩MV对裂缝尖端应力场的影响，导致所得混凝土断裂韧度值表现出一定程度的尺寸效应，但当采取措施消除此影响或此影响较小时，楔入劈拉试件的断裂韧度值也将无明显的尺寸效应；在相同配合比、相同高度条件下，不同试件形式的双K断裂韧度值无明显的差异。因此，可认为混凝土双K断裂参数是描述混凝土结构裂缝起裂及失稳断裂过程的材料常数，与试样类型和尺寸无关。
关键词：混凝土断裂试验规程；双K断裂模型；三点弯曲梁；楔入劈拉试件；尺寸效应；形状效应；起裂荷载

An experimental study on double-K fracture parameters of concrete for dam construction with various grading aggregates

Xu Shilang1 Zhou Hougui2 Gao Hongbo1 Zhao Shouyang 2
（1. The State Key Laboratory of Coastal and Offshore Engineering, Dalian University of
Technology, Dalian 116024, China; 2. China Gezhouba Group Corporation, Yichang 443002, China）

Abstract: To further provide sufficient test data for formulating the norm fracture of hydro-engineering concrete in China, as suggested by the committee on norm concrete fracture test, a series of fracture tests were performed on a total of 140 specimens via three-point bending and wedge-splitting, with the maximum dimensions being S×D×B=2200 mm×550 mm×240 mm and 2H×D×B=1200 mm×1200 mm×250 mm respectively. With the arrangement of electric resistance strain gauges, the load vs. strain curves are obtained, and the initial cracking load and maximum load are specified. Double-K fracture parameters are calculated, and discussions on the size effect and geometry effect are also made. The results indicate that it is feasible to measure the initial cracking load by using electric resistance strain gauge and the ratio of the initial cracking load to the unstable fracture load that approximately falls into the range from 0.6 to 0.85. Based on the test results of three-point bending of beams, the double-K fracture parameters are rather size-independent. While for the wedge-splitting specimens, the influence of additional vertical load induced moment on the stress field around the crack tip enables the double-K fracture parameters to exhibit size effect to some extent. However, when eliminating or reducing such influence, wedge-splitting geometry has no obvious size effect on the double-K fracture parameters. The double-K fracture parameters, determined from using the same concrete and depth but different geometries are comparable, indicating that the double-K fracture parameters are independent of size and geometry and can be treated as the fracture parameters to describe fracture initiation and instability for crack propagation in concrete structures.
Keywords: concrete fracture test norm; double-K fracture model; three-point bending beam; wedge-splitting specimen; size effect；geometry effect；initial cracking load
E-mail: slxu@dlut.edu.cn

钢纤维混凝土抗拉性能试验研究

韩 嵘1 赵顺波2 曲福来3
（1．北京交通大学，北京 100044；2．华北水利水电学院，河南郑州 450011；
3．大连理工大学，辽宁大连 116024）

摘要：研究了钢纤维体积率、钢纤维长径比、钢纤维类型对钢纤维混凝土劈裂抗拉强度、轴心抗拉强度及轴心受拉应力-应变全曲线的影响规律。试验采用两端埋设钢筋的变截面轴心受拉试件并在普通万能试验机上加辅助刚性架，进行钢纤维混凝土轴心受拉应力-应变全曲线测试。研究表明，随着钢纤维体积率、长径比的增大，钢纤维混凝土劈裂抗拉强度、轴心抗拉强度呈线性增大规律。采用设计的试验装置可测得钢纤维混凝土轴心受拉应力-应变全曲线，分析了纤维掺量和基体混凝土强度对轴心受拉应力-应变全曲线的影响规律。根据试验数据分析，提出了钢纤维混凝土轴心抗拉强度与劈裂抗拉强度间的关系式，提出了钢纤维混凝土轴心受拉应力-应变全曲线的解析表达式。
关键词：钢纤维混凝土；轴心抗拉强度；劈裂抗拉强度；应力-应变全曲线

Experimental study on the tensile performance of steel flber reinforced concrete

Han Rong1 Zhao Shunbo2 Qu Fulai3
(1．Beijing Jiaotong University，Beijing 100044，China；2．North China University of Water Conservancy and Electric Power，Zhengzhou 450011，China；3．Dalian University of Technology，Dalian 116024，China)

Abstract: The effects of steel fiber volumetric ratio, steel fiber slenderness ratio and steel fiber type on the splitting tensile strength, axial tensile strength and axial tensile stress-strain curve of steel fiber reinforced concrete (SFRC) are studied. In axial tensile stress-strain SFRC tests, axial tensile specimens of various cross-sections with embedded end reinforcements are tested in an ordinary universal test machine with a subsidiary rigid frame added. The results indicate that both the splitting tensile strength and the axial tensile strength of SFRC increase with the increasing of the steel fiber volumetric ratio and the steel fiber slenderness ratio. Axial tensile stress-strain curves of SFRC are obtained. The effects of the steel fiber volumetric ratio and the concrete strength on the axial tensile stress-strain curve are studied. A relationship between the axial tensile strength and the splitting tensile strength of SFRC is proposed. An analytical formula for the axial tensile stress-strain relationship of SFRC is proposed.
Keywords: steel fiber reinforced concrete (SFRC)；axial tensile strength；splitting tensile strength；stress-strain full curve
E-mail: hrhanrong@163.com

绥芬河青云市场套（扩）建工程结构设计与施工措施研究

郑文忠1 刘 铁1 谭 军1 解恒燕1 李忠民2
（1. 哈尔滨工业大学 ，黑龙江哈尔滨150090；
2. 绥芬河市青云经贸有限公司，黑龙江绥芬河157300 ）

摘要：结合绥芬河青云市场套（扩）建改造工程实践，提出了在施工阶段只在原房屋结构顶侧实现新增套（扩）建框架与原房屋框架的类链杆连接，待新增套（扩）建结构沉降充分后，再实现新旧结构在各层的链杆连接的设计思路。通过在原结构顶与外套框架柱间设置混凝土垫块，并在二外套框架柱间布置并张拉预应力筋，来实现施工阶段外套框架柱与原结构顶的类链杆连接。在新增结构施工完成后，将原结构顶上皮标高处二外套框架柱中预埋钢筋焊接连通，并浇筑一定厚度混凝土，来实现在原结构顶标高处新旧结构间的永久性可靠连接。将原框架节点的后植钢筋与外套框架柱的预埋钢筋焊接连接，来实现新旧结构在各层的链杆连接。为确保施工过程中原房屋的正常使用，提出了用挂模钢桁架来承托内置钢桁架－混凝土组合框架梁施工阶段荷载，用挂模钢箱来承托内置钢箱－混凝土组合次梁施工阶段荷载，用垂直于次梁内置钢箱焊接的型钢主楞来承托楼板荷载的施工阶段自承重混凝土楼盖设计与施工方法。
关键词：套（扩）建工程；预应力；内置钢桁架－混凝土组合框架梁；内置钢箱－混凝土组合次梁

Design methods and construction techniques for the outer-jacketing structure reconstruction(extension)project of the Suifenhe Qingyun Market

Zheng Wenzhong1 Liu Tie1 Tan Jun1 Xie Hengyan1 Li Zhongmin2
（1. Harbin Institute of Technology, Harbin150090，China;
2. SuiFenHe Trading Co., Ltd., Suifenhe157300, China）

Abstract: In connection with the reconstruction(extension)project of the Suifenhe Qingyun Market, a design approach is proposed, in which similar links are employed to connect the newly-added frame and the original structure only at the roof of the original building, and the new structure and the original structure are connected by links at each floor after settlement of the new structure is complete. Similar connections between the original structure and the outer-jacketing frame columns are formed during construction by using concrete blocks placed between the roof of the original building and the outer-jacketing frame columns and by prestressing the reinforcing tendons between the two outer columns. After the new structure is constructed, steel bars embedded in the two outer columns at the height of the roof of the original building are welded together, and concrete of a certain depth is cast. In this way, the permanent firm connection between the roof of the original structure and the new structure is formed. The post-installed steel bars in the original frame joints are welded with embedded steel bars in the outer columns to work as the connection at each floor. In order to ensure that the original building works as usual during the construction, the design and construction methods of self-supporting concrete floor during construction are presented, the main idea of which is that the steel truss suspended by formwork can bear the construction load of encased steel-truss-concrete composite beam, that the steel box suspended by formwork can support the construction load of encased steel-box-concrete composite beam, and that the channel welded perpendicular to the encased steel box can carry the floor load.
Keywords: reconstruction(extension)project; prestress; encased steel truss-concrete composite frame beam; encased steel box-concrete composite secondary beam
E-mail: zhenwenzhong@hit.edu.cn

在弯矩、剪力和反复扭矩复合作用下的碳纤维布
加固RC箱梁抗扭性能试验研究

李忠献 景 萌
（天津大学，天津300072）

摘要：为研究碳纤维布加固弯矩、剪力和反复扭矩复合作用下的钢筋混凝土箱梁的抗扭性能，共设计制作了4根钢筋混凝土箱梁试件，其中3根采取碳纤维布加固、1根不加固作为对比试件。试验在自行研制的扭转试验装置上进行，对箱梁试件同步施加弯矩、剪力和反复扭矩作用。以加固方式和加固数量为主要研究参数，分析了箱梁试件的破坏机理、承载能力、变形能力和滞回性能等。通过各箱梁试件的碳纤维布和钢筋的应变变化规律，探讨了碳纤维布加固箱梁的抗扭工作机理；通过测得的各试件的扭矩-扭转角滞回曲线和骨架曲线，提出了碳纤维布加固钢筋混凝土箱梁的抗扭恢复力模型。从而为碳纤维布加固钢筋混凝土箱梁抗扭性能的理论研究和工程应用提供了重要的依据。
关键词：钢筋混凝土箱梁；抗扭性能；加固；碳纤维布；复合作用；反复扭矩

Experiments on the torsional behavior of FRP strengthened RC box beams
subjected to combined action with cyclic torque

Li Zhongxian Jing Meng
(Tianjin University, Tianjin 300072, China)

Abstract: Experiments on the torsional behavior of RC box beams strengthened with fiber-reinforced polymer (FRP) laminates are performed under the combined action of bending moment, shear and cyclic torque. Four RC box beams are designed and fabricated, of which, three are strengthened with FRP laminates and one is kept as original for comparison purpose. The tests were run on a self-manufactured torsion test apparatus, and the box beams are synchronously subjected to bending moment, shear and cyclic torque. Take the strengthening scheme and the number of FRP layers as the main parameters, the failure mode, torsion capacity, deformation capacity and hysteresis behavior of the specimens are investigated. According to the change of strains in FRP and reinforcement, the torsional mechanism of the FRP strengthened box beams is discussed. Based on the hysteresis and the torque vs. twist-angle curves, a model is developed for the torsional recovering force of the FRP strengthened box beams, which provides an important reference for theoretical study and engineering application of the FRP torsional reinforcement to RC box beams.
Keywords: reinforced concrete(RC)box beam; torsional behaviour; strengthening; fiber-reinforced polymer (FRP) laminate; combined action; cyclic torque
E-mail: zxli@tju.edu.cn

自锚式悬索桥磁流变阻尼器减震控制研究

杨孟刚1，2 陈政清2 胡建华3
（1.中南大学，湖南长沙410075；2.湖南大学，湖南长沙410082；
3. 湖南省交通规划勘察设计院，湖南长沙410008）

摘要：为了减小自锚式悬索桥的地震响应，基于桥梁结构地震动力方程及磁流变阻尼器力学模型，建立桥梁结构—磁流变阻尼器减震系统并将其程序化，对某主跨350 m的独塔自锚式悬索桥进行减震控制研究，讨论了磁流变阻尼器输入电流、数目及安装位置对减震效果的影响。研究结果表明：采用磁流变阻尼器能够有效地减小自锚式悬索桥的纵向地震响应；随安装在塔梁之间顺桥向的磁流变阻尼器输入电流的增大及数目的增加，塔顶和主梁的纵向位移逐渐减小，结构的内力响应也得到有效控制；将全部磁流变阻尼器安装在塔梁之间顺桥向时减震效果最佳。
关键词：悬索桥；自锚式；磁流变阻尼器；减震控制

Study on the seismic response control of self-anchored suspension bridges with MR dampers

Yang Menggang 1，2 Chen Zhengqing 2 Hu Jianhua 3
（1.Central South University, Changsha 410075, China; 2. Hunan University, Changsha 410082, China;3. Hunan Provincial Communications Planning, Survey and Design Institute, Changsha 410008, China）

Abstract: To mitigate the seismic response of self-anchored suspension bridges, based on the earthquake dynamic equation of bridge structure and a mechanical model of magnetic-rheological (MR) damper, a system composed of the bridge structure and the MR damper is established, and a computer program is developed and employed for studying the seismic response control of a single-tower self-anchored suspension bridge with a main span of 350m. The effect of seismic response control via variable current, number and setting position of MR dampers is discussed. The study indicates that MR dampers can effectively reduce the longitudinal seismic response of self-anchored suspension bridges. With increase in the input current and the number of MR dampers between the main tower and the main girder in the longitudinal bridge direction, the longitudinal displacements of the tower top and the main girder decrease, and the internal force response of the structure can effectively be controlled. The best effect of seismic response control would be reached when all MR dampers are placed between the main tower and the main girder in the longitudinal bridge direction.
Keywords: suspension bridge; self-anchored; MR damper; seismic response control
E-mail: mgyang@mail.csu.edu.cn

桥梁中抗震限位装置设计方法的研究

王军文1 李建中2 范立础2
（1. 石家庄铁道学院，河北石家庄050043；2. 同济大学，上海200092）

摘要：为防止桥梁上部结构在地震中发生落梁破坏，通常在伸缩缝处安装限位装置。在调查影响伸缩缝处相邻梁体相对位移因素的基础上，根据线性化模型提出一种限位装置设计方法。该方法既考虑了相邻桥跨不同向振动的动力特性，又考虑了相邻梁体间碰撞对相对位移的影响。运用替代结构法考虑墩柱的弹塑性，使用考虑碰撞效应的相对位移反应谱考虑碰撞对相对位移的影响。通过参数研究对提出的限位装置设计方法的可靠性进行验证，并通过与已有的限位装置设计方法相比，评估了所提出的限位装置设计方法的限位效果。与已有的设计方法相比，本文提出的限位装置设计方法与非线性时程分析结果的相关性更好。
关键词：地震；桥梁；碰撞；限位装置；设计方法；地震反应

A study on the design method of seismic restrainers for bridges

Wang Junwen1 Li Jianzhong2 Fan Lichu2
（1. Shijiazhuang Railway Institute, Shijiazhuang 050043, China；2. Tongji University, Shanghai 200092, China）

Abstract: Seismic restrainers are often needed at expansion joints of bridges to prevent the superstructures from falling off during earthquakes. Factors affecting the relative displacement between bridge segments at expansion joints are investigated, and a design procedure for restrainers, based on a linearized model, is developed. This restrainer design procedure not only takes into consideration the dynamic characteristic out-of-phase motion of adjacent bridge segments, but also the effect on the relative displacement due to impact between bridge segments. Inelastic behavior of piers is represented by using the substitute structure method, and the effect of impact on relative displacement is considered by using the relative displacement response spectra with impact effect. Reliability of the proposed restrainer design procedure is validated through parametric studies, and the effect of this restrainer design procedure in limiting relative displacement is assessed by comparing with existing restrainer design procedures. The results of the studies indicate that, comparing with existing restrainer design procedures, the restrainers designed from using proposed procedure are more consistent with those from nonlinear time-history analysis.
Keywords: earthquake; bridge; pounding; restrainer; design procedure; seismic response
E-mail：wjunwen2901@163.com

黄土地区单片地下连续墙水平承载特性试验研究

孟凡超1 李 涛2 陈晓东1 龚维明2
（1.中交公路规划设计院，北京100010；2.东南大学，江苏南京210096）

摘要：黄土地区某拱桥采用较为新颖的井筒式地下连续墙基础。为研究基础的水平承载特性，对单片地下连续墙进行了水平荷载试验。在墙身中布置钢筋计、测斜管，墙背布置土压力盒，采用慢速维持荷载法进行水平加载，试验时采集了墙顶、墙身位移、墙身应变、墙侧土抗力等现场数据，绘制了水平荷载H与力作用点处位移Y关系曲线。根据墙身实测应变采用标定断面法和理论计算法推算墙身弯矩，根据弹性地基梁理论由墙身弯矩推算墙侧土抗力，并与墙侧实测土抗力进行了对比分析。分析得出了单片墙水平承载力、不同深度处土抗力和水平位移关系图（q-y曲线），并推算了设计所需的土水平抗力系数的比例系数m值。试验和分析结果为黄土地区井筒式地下连续墙基础设计提供了重要依据。
关键词：地下连续墙基础；单片墙；水平荷载；水平位移；墙身弯矩；土抗力；m值

Test on the lateral bearing behavior of a diaphragm wall in loess area

Meng Fanchao1 Li Tao2 Chen Xiaodong 1 Gong Weiming 2
(1.China Highway Planning and Design Institute Consultants, INC., Beijing100010,China;
2. Southeast University, Nanjing 210096, China)

Abstract: As a new type of foundation, the shaft diaphragm wall is employed for an arched bridge in loess area. To study the lateral bearing behavior, one single diaphragm wall is tested under lateral load. Strain gauges and deflection inclinometer are embedded inside the wall, and pressure cells are embedded at the back side of the wall. Slow sustaining load is applied in the test, the displacement, strain and soil resistance data are collected, and relationship between the lateral load, H, and the displacement, Y, is derived. The bending moment is calculated from the strain by using the calibrated section method and the theoretical method, soil resistance is calculated from the bending moment according to the elastic foundation beam theory, and comparisons with the actual values are conducted. The lateral bearing capacity, internal force and lateral displacement of the single diaphragm wall, the distribution of soil resistance, the relationship between soil resistance and lateral displacement at different depths (q-y curve) and the m-value of the lateral subgrade coefficient are calculated through analyzing the test data.
Keywords: diaphragm wall foundation; single diaphragm wall; lateral load; lateral displacement; bending moment in wall; soil resistance; m-value
E-mail: chenxiaodongsir@vip.sina.com

火灾工况下公路隧道竖井通风模式试验研究

闫治国1 杨其新2 王明年2 朱合华1
（1．同济大学，上海 200092； 2．西南交通大学，四川成都 610031）

摘要：为了建立火灾工况下有效的竖井通风模式，通过大比例火灾模型试验，对不同通风模式下，主隧道、风道及竖井内温度场的传播分布、烟流蔓延扩散规律进行了研究。试验模型隧道长100 m，内径1.8 m，设有直径1 m的送风竖井、排风竖井各一座。火源采用燃烧床盛放油料模拟，试验中设定了A、B、C三个火灾规模用以模拟实际隧道火灾场景，考虑了三个火灾位置：火灾位置I、II和III。试验结果表明随着通风风速、火灾规模、火灾位置的不同，隧道、通风道及竖井内温度场分布及烟流流动差异很大，而且随着时间的推移，其分布发生显著变化。这表明当隧道中发生火灾时，应根据火灾点与竖井的相对位置分阶段，实施不同的通风模式。基于试验结果，建议了秦岭隧道火灾时的有效通风模式。
关键词：公路隧道； 火灾； 火灾试验； 通风模式

Experimental study of shaft ventilation modes for road tunnels in case of fire

Yan Zhiguo1 Yang Qixin2 Wang Mingnian3 Zhu Hehua1
（1．Tongji University， Shanghai 200092，China；
2．Southwest Jiaotong University，Chengdu 610031，China）

Abstract: To establish an effective ventilation mode for fire fighting in the Qinling road tunnel, an experiment is carried out to study the temperature distribution and smoke propagation in the ventilation duct and shaft of the tunnel in case of fire.. The model tunnel is 100 m long, has a circular cross-section with an inner diameter of 1.8 m. Two ventilation shafts with a diameter of 1 m are constructed. An oil pool is employed as the source of fire. Three fire loads and three fire locations are employed to simulate different fire scenarios. The results indicate that the temperature distribution and smoke propagation vary significantly with different fire loads, fire locations, ventilation modes and fire stages in the tunnel, the ventilation duct and the shaft. These phenomena suggest that different ventilation modes, in case of fire, should be considered in order to show a consistent effect with the fire locations and fire stages. Based on the results of the experiments, an effective ventilation mode is established for fire fighting in the Qinling tunnel.
Keywords: road tunnel；tunnel fire；experimental study；ventilation mode
E-mail: yanzguo@126.com

基于信号处理技术的ITS数据压缩方法与应用

耿彦斌1 于 雷2，3 武 旭2 刘梦涵2 赵 慧2 吴家庆4
（1. 交通部规划研究院，北京100029；2. 北京交通大学，北京100044；3. 德克萨斯南方大学，美国休斯敦 77004；4. 北京公共交通控股（集团）有限公司，北京 100073）

摘要：当前智能交通系统(ITS)数据采集技术的飞速发展所引发的ITS数据海量特性，将严重妨碍数据在交通系统内的存储、传输和发布。在ITS数据自身特征分析的基础上，利用信号处理领域中的小波变换、离散余弦变换、量化和编码技术，通过设计适当的特征抽取阈值和量化器，提出了有限失真条件下（以一定的失真为代价）的高效ITS数据压缩与重构方法。压缩的出发点是在控制失真度的前提下，尽可能多的保留有用信息。通过对北京市三环路上的交通流数据进行测试，表明采用本文提出的数据压缩方法与常用的无损压缩方法（WinZip软件）相比，能够将文件的压缩幅度相对提高61.92%，且重构数据中与原始数据差值大于1的记录仅占1.27%，证明在有限的失真度前提下压缩效果得到明显改善。
关键词：智能交通系统(ITS)；数据压缩；小波变换；失真度；量化

Signal-processing-based ITS data compression techniques and applications

Geng Yanbin1 Yu Lei2，3 Wu Xu2 Liu Menghan2 Zhao Hui2 Wu Jiaqing 4
(1. Transport Planning and Research Institute, Ministry of Communications, Beijing 100029, China;2. Beijing Jiaotong University, Beijing 100044, China; 3. Texas Southern University,
Houston TX 77004, U.S.A; 4. Beijing Public Transport Holdings, Ltd., Beijing 100073, China)

Abstract: The rapid development of Intelligent Transportation Systems (ITS) data collection technologies has generated massive ITS data, presenting a critical obstacle to storing, transmitting and disseminating the data within the transportation system. After analyzing the characteristics of ITS data, this paper proposes a highly effective ITS data compression and reconstruction approach with a limited distortion by designing the appropriate feature-distilling threshold and quantizer, based on the Wavelet Transform, Discrete Cosine Transform (DCT), and Quantizing and Coding techniques for signal-processing. The objective of the compression is to minimize the data redundancy, keep the maximum amount of useful information and limit the level of distortion. Test on the traffic flow data of the 3rd ring expressway in Beijing demonstrates that the proposed technique has increased the compression rate by 61.92 percent in comparison with the widely used lossless compression approach (WinZip software), and that only 1.27 percent of the data has shown a larger-than-five-percent error between the reconstructed and the original raw data. This indicates that the proposed technique can significantly improve the effectiveness of compression with a limited distortion.
Keywords: Intelligent Transportation Systems (ITS); data compression; wavelet transform; degree of distortion; quantizing
E-mail: ybgeng@tom.com

环境目标下城市交通综合网络设计的优化模型及求解算法

张好智 高自友 张 贝
（北京交通大学，北京100044）

摘要：机动车尾气排放因子（emission factor）、路段行驶时间和交叉口等待时间等都是影响城市交通尾气总排放量的重要因素。而城市交通网络中路段通行能力的改善或者交叉口信号配时方案的调整都会直接影响机动车尾气排放因子和交通出行时间的变化，从而影响城市交通尾气总排放量的大小。为此，首先根据机动车在路段上的行驶状况，引入两个与出行时间关联的尾气排放因子，即路段正常行驶时的尾气排放因子和交叉口排队等待时的尾气排放因子，进而给出适用于城市交通网络设计问题的尾气总排放量计算公式；然后用双层规划方法综合优化信号灯配时方案和道路能力改善方案，以达到最大程度地降低交通尾气总排放量的目的。基于粒子群优化算法，设计了一个求解该双层模型的全局优化算法，该算法操作简单，易于实现，并用一个简单算例验证了本文模型与算法的有效性。
关键词：交通尾气；道路网络设计；交通信号设置；双层规划；粒子群优化

Model and algorithm of transportation network design for emission reduction

Zhang Haozhi Gao Ziyou Zhang Bei
(Beijing Jiaotong University, Beijing 100044, China)

Abstract: The total emissions in congested urban transportation networks depend significantly on the emission factor, the road traveling time and the intersection delay. Road capacity enhancement and signal timing adjustment directly affect the emission factor, the road traveling time and the intersection delay, and consequently the total emissions. Therefore, two speed-related emission factors, i.e., the road-traveling emission factor and the intersection-queuing emission factor, are introduced, according to the vehicle traveling condition, and a formula for total-emission calculation, applicable to transportation network design, is proposed. Signal timing and road network design problems are simultaneously optimized to minimize the total emissions by using the bi-level programming approach. The bi-level programming model can determine the optimal road capacity enhancement and the optimal signal circle and signal split with the objective being total emission minimization. Based on the Particle Swarm Optimization (PSO) algorithm, a simple global solution algorithm is designed for the bi-level programming model. An example is presented to verify the proposed model and algorithm.
Keywords: transportation emission; road network design; signal timing; bi-level programming; particle swarm optimization
E-mail: haozhizhang7@126.com

基于治理的政府投资项目代建制绩效改善研究

严 玲 尹贻林
（天津理工大学，天津300072）

摘要：政府投资项目在我国经济生活中发挥着重要作用。在政府投资项目行政代理制度下，项目管理绩效不高，导致项目绩效也不佳。国内推行的政府投资项目代建制管理模式就是针对行政代理制度下的弊端展开的一项改革措施。研究围绕国内推行的代建制改革是否有效，如何改善代建制绩效而展开。在项目治理的新范式和研究框架下，探讨了不同时期我国政府投资项目治理模式演变和企业型代建制下的项目所有权配置，建立了相应的代建制治理水平初步评价指标，在此基础上从制度层面对政府投资项目代建方案进行了设计。研究结果表明，我国代建制发展方向为企业型代建，对该代建模式下所形成的治理结构的改善需要通过内部治理和外部治理以及政府监督机制等三个途径实现。
关键词：政府投资项目；代建制；项目治理；治理水平；改善途径

Management performance improvement of agent system for
government invested construction projects

Yan Ling Yin Yilin
（Tianjin University of Technology, Tianjin 300072, China）

Abstract: Government investment projects play important roles in the economy of China. However, the current administration agent system of public projects has resulted in low efficiency in the work performance. As one of the significant reform methods, an agent construction system still has some aspects that need to be improved. Whether the reformation of an agent construction system is more effective and how to improve its performance are the issues discussed in the paper. In the framework of a new paradigm of project governance, the evolution of governance model of public projects is explored, whereas the project ownership arrangement in the context of administration agent system is analyzed. Moreover, the corresponding primary evaluation indexes of governance level are set up together with the agent construction program.. In conclusion, a new paradigm of the project governance theory to improve the management performance of agent construction system is established, including three routes: internal project governance, external project governance and government supervised mechanism.
Keywords: public project; agent construction system; project governance structure; evaluate index of governance level; project performance improvement
E-mail: lingyantj@163.com