跨地裂缝三孔斜交箱涵结构受力性能和变形规律研究  

Mechanical behavior and deformation laws of three hole oblique box culvert structure crossing ground fissure

作　　者：吴涛[1] 陈顺 刘喜[1] 李乐宇 Wu Tao;Chen Shun;Liu Xi;Li Leyu(Chang’an University,Xi’an 710061,China)

机构地区：[1]长安大学,陕西西安710061

出　　处：《土木工程学报》2024年第8期23-35,共13页China Civil Engineering Journal

基　　金：国家自然科学基金(52078042);陕西省重点研发计划(2022GY-425,2022SF-608);陕西省自然科学基金基础研究计划(2022KJXX-03)。

摘　　要：以西安站改扩建项目为工程背景,完成足尺三孔斜交箱涵结构受力性能数值模拟研究,分析荷载与地裂缝协同作用下结构的受力过程与可能破坏形态,开展缩尺比例为1∶15的三孔斜交箱涵缩尺模型静载试验,与有限元结果进行对比分析,明确变形缝斜交和板墙开洞等复杂条件下箱涵结构的裂缝发展、位移变形和应力分布规律,验证了数值分析的可行性,并提出设计建议。结果表明:足尺数值模型与缩尺试验模型的应力路径和裂缝分布吻合较好;最不利工况下,箱涵顶板混凝土开裂部位较多,纵向挠度变形较小;斜交变形缝处,钝角较锐角处更易产生应力集中现象,各部位易出现应力集中的顺序依次为跨中、钝角、锐角和板墙隅角;采用平行于变形缝的斜向布筋方式可降低因钢筋截断而产生的应力集中,优化传力路径;建议在顶板洞口横向位置处增设暗梁,洞角布置斜向钢筋,降低洞口周围的局部集中应力。With the background of the Xi’an Station Improvement Project,the numerical simulation study on the mechanical behavior of a full⁃scale three hole oblique box culvert was conducted,and the mechanic characteristics and possible damage patterns of the structure under the combined action of load and ground fissure were analyzed.A 1∶15 reduced⁃scale model of the three⁃hole oblique box culvert was tested by the static loading,and the test results were comparatively analyzed with the results by the finite element method.The laws of crack development,displacement deformation and stress distribution of box culvert structures under the combined effect of the oblique deformation joint and the openings in the slabs and walls were clarified.The reliability of the numerical analysis was verified,and corresponding design suggestions were proposed.The results showed that the stress paths and crack distributions of the full⁃scale numerical model agreed well with those of the reduced⁃scale test model.Under the worst operating condition,the concrete cracking parts of the box culvert top slab were obvious,while the longitudinal deflection deformation was small.At the oblique deformation joints,the obtuse angle was more prone to stress concentration than the acute angle.The sequence of the parts prone to stress concentration was respectively the midspan,the obtuse angle,the acute angle and corner of the slab and wall.Adopting an oblique reinforcement arrangement parallel to the deformation joint can reduce stress concentration caused by steel bar truncation and optimize the force transmission path.It is suggested to add the concealed beams at the lateral position of the openings and the diagonal steel bars at the corner of the openings to weaken the local stress.

关 键 词：斜交箱涵 三孔结构 墙板开洞 地裂缝 静载试验 有限元分析 

分 类 号：TU931[建筑科学—结构工程]