高边坡复合支挡结构抗震设计方法与试验研究

Composite retaining structure is a widely used structure to support the high slope. However, due to the lack of systematic research results, the seismic design theory of composite retaining structure is far behind the engineering practice. Based on two typical composite retaining structures which are namely called as "gravity retaining wall + anchor frame beam" and "pile-board wall + anchor frame beam", shaking table test and numerical simulation are performed to investigate the dynamic response of composite retaining structure subject to different earthquake excitations. The effects of parameters as well as their significance on the seismic behavior of composite retaining structure are analyzed. The mechanical mechanism and the dynamic failure mode of composite retaining structure are revealed. The kinematic failure mode of composite retaining structure is established based on upper bound theory of limit analysis method, and the strength calculation formulas are obtained in terms of the seismic safety coefficient, the soil pressure on retaining wall, the resistance of retaining wall, the axial force of anchor, the yield acceleration, and so on. The calculation method of seismic permanent deformation is studied based on the idea of Newmark sliding method. Combined with the results of shaking table test and numerical simulation, the calculation methods which apply to the evaluation of the seismic stability and the deformation characteristics of composite retaining structure are put forward. The seismic calculation program is designed for composite retaining structure, and the shaking table test and numerical simulation modules are embedded into the program. The research work will recommend an effective calculation method for seismic design of composite retaining structure, and the research results will be incorporated into the "Code for Seismic Design of Railway Engineering".

复合支挡结构广泛应用于高边坡结构支护，但由于缺乏系统的研究成果，复合支挡结构的抗震设计理论已远落后于工程实践。本项目以“重力式挡墙+锚杆框架梁”和“桩板墙+锚杆框架梁”两种典型的复合支挡结构为研究对象，通过振动台试验和数值模拟研究不同地震动激励下复合支挡结构的动力响应特性，分析其抗震特性的影响参数及其显著性，揭示复合支挡结构的力学作用机理和动力破坏模式；基于极限分析法上限定理构建复合支挡结构的运动破坏机构，推导地震安全系数、墙背土压力、挡墙抗力、锚杆轴力、屈服加速度等强度计算公式，并基于Newmark滑块思想研究地震永久变形的计算方法；结合振动台试验和数值模拟结果，提出适合于复合支挡结构地震稳定性及其变形特性的分析方法；开发复合支挡结构抗震计算程序，并嵌入振动台试验和数值模拟模块。本研究项目将为复合支挡结构抗震设计推荐有效的计算方法，研究成果力争纳入《铁路工程抗震设计规范》。

我国强震频发，造成了大量边坡和支护结构破坏。我国的铁路和公路抗震设计规范仅推荐了单级、均质边坡地震稳定性计算的圆弧条分法，支挡结构的抗震设计理论水平已远落后于工程实践。本项目以“重力式挡墙+锚杆框架梁”、“桩板墙+锚杆框架梁”等典型复合支护结构为研究对象，通过振动台试验、数值模拟、理论分析、程序开发等研究手段，分析了高边坡复合支挡结构的力学特性和抗震性能，推导了复合支挡结构地震稳定性理论公式，开发了地震分析程序。主要工作有：.（1）“重力式挡墙+锚杆框架梁”复合支挡结构的抗震分析。通过振动台试验和三维数值仿真手段，揭示了“重力式挡墙+锚杆框架梁”复合支挡结构的水平和竖直加速度、地震土压力、挡墙位移、锚杆轴力的响应规律，验证了“重力式挡墙+锚杆框架梁”的刚、柔组合理念在地震高烈度区的可行性，分析了边坡破坏面对复合支挡结构抗震性能的影响，推导了“重力式挡墙+锚杆框架梁”复合支挡结构地震稳定性分析理论公式，并开发了复合支挡结构抗震分析计算软件。.（2）“桩板墙+锚杆框架梁”复合支护结构的抗震分析。通过振动台试验和三维数值仿真手段，研究了桩板墙+锚杆框架梁的水平和竖直加速度响应、地震土压力响应、锚杆轴力响应以及桩、板相互作用的力学特性。推导了地震作用下“桩板墙+锚杆框架梁”复合支挡结构的强度计算公式，为桩板墙+锚杆框架梁复合支挡结构的抗震设防和抗震设计提供了建议和依据。.项目以工程需求为出发点，获得了复合支挡结构地震响应新发现，提出了抗震计算方法。研究成果为高边坡支护和复合支挡结构抗震设计提供科学依据和重要价值。