土工格栅加筋软土路基时效性与地震动力响应特性分析

发布时间：2018-09-13 09:25

【摘要】：作为一种新型的岩土工程材料,土工格栅已被广泛应用于各个工程领域。近年来随着高速公路建设的迅速发展,很多高速公路不可避免地建设在软土地基上,而格栅加筋作为一种行之有效的软基加固方法,在各类工程软基加固中取得了良好的效果,但该法的加固机理及其影响因素等诸多方面仍存在很多不明之处。本文在前人工作的基础上,基于大型有限元数值计算平台ADINA,建立土工格栅加筋软土路堤平面应变模型,综合考虑孔隙水的影响,对加筋路堤体系进行参数敏感性分析评价其时效性。在此基础上利用动力时程逐步时间积分法,对加筋路堤体系进行地震动力响应分析。具体研究内容包括:(1)针对加筋路堤体系进行了等效静力计算,分析了加筋软土路堤在重力和行车荷载作用下的固结沉降引起的应力重分布及变形;在此基础上对加筋路堤体系中各种参数(加筋方式、间距、层数、模量以及路基土弹性模量、路堤土内摩擦角、泊松比和黏聚力)进行等效静力计算,分析不同参数变化对加筋路堤体系受力及变形的影响规律,计算结果表明:加筋方式、间距以及路堤土内摩擦角和黏聚力对加筋路堤体系特性影响较大,针对这些参数,通过正交试验设计进行参数化分析,获得这些参数具体的影响系数,得到结果为路堤土内摩擦角为影响系数最大的参数,黏聚力次之。(2)选取典型强震记录El-centro波,分析了不同地震波强度对加筋路堤体系地震动力响应的影响,然后通过对比计算有无孔隙水两种工况,分析孔隙水对体系地震动力响应的影响。在此基础上,对饱和软土场地上加筋路堤体系进行了参数化分析,进一步分析不同参数对加筋路堤体系地震动力响应的影响规律。
[Abstract]:As a new geotechnical engineering material, geogrid has been widely used in various engineering fields. In recent years, with the rapid development of highway construction, many expressways are inevitably built on soft soil foundation. As an effective method of soft foundation reinforcement, grille reinforcement has achieved good results in all kinds of projects. However, the reinforcement mechanism and influencing factors of the method are still unknown. Based on the previous work, the plane strain model of geogrid reinforced soft soil embankment is established based on the large finite element numerical calculation platform ADINA, and the influence of pore water is considered synthetically. The parameter sensitivity analysis of reinforced embankment system is carried out to evaluate its timeliness. On this basis, the seismic dynamic response of reinforced embankment system is analyzed by using the time integration method of dynamic time history step by step. The specific research contents are as follows: (1) the equivalent static calculation of reinforced embankment system is carried out, and the stress redistribution and deformation caused by consolidation settlement of reinforced soft soil embankment under the action of gravity and driving load are analyzed. On this basis, the equivalent static calculation of various parameters (reinforcement mode, spacing, layer number, modulus and elastic modulus of embankment soil, internal friction angle of embankment soil, Poisson's ratio and cohesive force) in reinforced embankment system is carried out. The effects of different parameters on the stress and deformation of reinforced embankment system are analyzed. The results show that the reinforced embankment system is greatly affected by the reinforcement mode, spacing, internal friction angle and cohesive force of embankment soil, and the characteristics of reinforced embankment system are greatly affected by these parameters. Through the parametric analysis of orthogonal test design, the specific influence coefficients of these parameters are obtained. The results show that the internal friction angle of embankment soil is the most influential parameter, followed by cohesion. (2) the typical strong earthquake record El-centro wave is selected. The influence of different seismic wave intensity on seismic dynamic response of reinforced embankment system is analyzed, and then the influence of pore water on seismic dynamic response of reinforced embankment system is analyzed by comparing with or without pore water. On this basis, the parameterized analysis of reinforced embankment system on saturated soft soil site is carried out, and the influence of different parameters on the seismic dynamic response of reinforced embankment system is further analyzed.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.12

【参考文献】