基于小主应力轨迹的上埋式涵管竖向土压力非线性描述  

Nonlinear descriptions of vertical earth pressure against positive buried pipelines based on minor principal stress trajectory

作　　者：张常光[1,2] 吴凯 隋建浩 ZHANG Chang-guang;WU Kai;SUI Jian-hao(School of Civil Engineering,Chang'an University,Xi'an 710061,China;Stake Key Laboratory of Geohazard Prevetion and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]长安大学建筑工程学院,陕西西安710061 [2]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《岩土工程学报》2021年第12期2200-2208,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(41202191);地质灾害防治与地质环境保护国家重点实验室开放基金项目(SKLGP2020K022);长安大学中央高校基本科研业务费专项资金项目(300102280108)。

摘　　要：针对上埋式涵管竖向土压力的非线性描述,考虑土拱效应和管土相对刚度的影响,建立了圆弧、抛物线和偏转角线性变化3种小主应力轨迹下上埋式涵管竖向土压力的非线性解答,继而结合等沉面高度确定给出应用步骤,并对比文献模型试验、现场实测和数值模拟验证了正确性和适用性,最后进行工程选用探讨。研究结果表明:所得解答合理呈现了上埋式涵管竖向土压力沿水平方向的非线性变化,具有广泛的理论意义和工程应用价值;3种小主应力轨迹解答的适用范围不尽相同,圆弧小主应力轨迹解答对低填方的刚性涵管和柔性涵管均有很好的适用性,偏转角线性变化小主应力轨迹解答常提供稍偏保守的土压力载荷,抛物线小主应力轨迹解答可应用于高填方柔性涵管但易出现明显的高估。This study presents a nonlinear solution of vertical earth pressure against positive buried pipelines with three kinds of minor principal stress trajectories,such as the circular arc,the parabolic curve,and the rotation angle linearly changed.The proposed solution accounts for the effects of soil arching and pipe-soil relative stiffness to capture the nonlinear descriptions of vertical earth pressure against the positive buried pipelines.Application steps of the proposed solution are provided along with determining the height of an equal settlement plane.Comparative validations of the results from the model tests,field measurements,and numerical simulations reported in the literatures are then performed.Finally,engineering application suggestions are discussed.It is found from this study that the proposed nonlinear solution can reasonably describe the nonlinear distribution of vertical earth pressure against the positive buried pipelines in the horizontal direction,which is of broad theoretical significance and engineering applicability value.Three solutions have different application scopes corresponding with three trajectories of minor principal stress.The solution of the circular arc trajectory is well applicable for both the shallow-filled rigid and the flexible pipelines.The solution of the rotation angle linearly changed trajectory commonly provides slightly conservative estimations of vertical earth pressures.The solution of the parabolic trajectory can be applied to high-filled flexible pipelines,yet obvious overestimations often occur.

关 键 词：上埋式涵管 竖向土压力 小主应力轨迹 土拱效应 管土相对刚度 等沉面高度 

分 类 号：TU432[建筑科学—岩土工程]