考虑地下管廊影响的结构地震响应分析与工程改进措施研究

INFLUENCE ANALYSIS OF UNDERGROUND PIPE GALLERY ON NONLINEAR SEISMIC RESPONSE OF UPPER STRUCTURE AND RESEARCH ON IMPROVEMENT MEASURES

城市地下管廊在修建后常常对上部的地面既有建筑在地震作用下的响应产生不利影响,在水平地震工况下,上部结构的不利影响相对无地下管廊影响的情况将被放大,甚至可能超出上部结构的正常使用范围。以某实际工程为背景,通过现行GB/T 51336—2018《地下结构抗震设计标准》建议的非线性时程分析方法分析上部建筑在地下管廊施工前后的地震响应,得到了管廊施工前后上部结构的地震响应差异并通过计算结果来分析产生差异的原因。通过模拟管廊周围地层注浆加固和调整管廊结构截面设计方法后的上部结构地震动响应,得出改善既有高层建筑地震动响应为目标的地下管廊施工控制措施。在实际工程完工后,现场提取加固前、后的土样进行了室内动三轴试验,得到的试验结果进一步佐证了注浆加固土体对地基土动力特性的改善效果及对上部结构地震响应的控制作用。

The urban underground pipe gallery often produces adverse effects on the deformation and uneven settlement of upper ground building after construction. Under the horizontal earthquake action after the construction of the underground pipe gallery, the adverse effects will be magnified, even beyond the normal use scope of the upper structure. Based on a practical project, the seismic response of the building structure before and after the construction of the underground pipe gallery was analyzed by the finite element method based on the nonlinear time history analysis proposed by Standard for Seismic Design of Underground Structures(GB/T 51336—2018). The seismic response difference of the structure before and after the construction of the pipe gallery was obtained, and the reasons for the difference were analyzed by using the calculation results. By simulating the design and construction measures of grouting reinforcement around the pipe gallery and adjusting the structural stiffness of the pipe gallery, the seismic response of the superstructure was obtained, and the effective control measures for improving the construction of the pipe gallery under the existing high-rise building were obtained. After the completion of the actual project, the soil samples before and after grouting reinforcement were extracted for indoor dynamic triaxial test. The test results could further support the improvement effect of grouting on the dynamic characteristics of foundation soil and the control effect on the seismic response of upper structure.