高填黄土明洞土拱效应及土压力减载模型分析

发布时间：2018-03-13 00:14

本文选题：明洞　切入点：减载效果　出处：《土木工程学报》2014年07期 　论文类型：期刊论文

【摘要】：通过室内模型试验研究高填方明洞土压力随填土高度的变化规律以及高填方明洞的拱效应,并比较以松散土体或EPS板做为变形层的减载效果及有无边坡对土压力的影响。试验结果表明:当填土达到一定高度后,明洞上方将产生土拱效应,拱顶部分土压力将由拱脚附近土体分担,由于土拱效应的不稳定性,使拱顶土压力随填土高度呈非线性规律变化,采用EPS板做为变形层的加筋减载效果优于松散土体,拱脚土压力受边界条件的影响较大。根据加筋减载原理和模型试验结果,建立了加筋减载力学计算模型,利用朗肯土压力理论,提出采取设置变形层和铺设土工格栅减载措施的高填方明洞顶的非线性土压力计算公式。通过现场试验证明土工格栅减载效果的有效性、耐久性以及本文计算方法的正确性,这对高填方明洞以及土工格栅减载结构的设计施工具有参考价值。
[Abstract]:The variation of soil pressure with filling height and the arch effect of high fill open tunnel are studied by laboratory model test. The load reduction effect of loose soil or EPS plate as deformation layer and the influence of slope on earth pressure are compared. The test results show that when the fill reaches a certain height, the soil arch effect will occur over the open tunnel. Part of the earth pressure of the arch roof will be shared by the soil near the arch foot. Because of the instability of the soil arch effect, the earth pressure of the arch roof changes with the filling height in a nonlinear manner. The reinforcement and load reduction effect of the EPS plate as the deformation layer is better than that of the loose soil. The earth pressure of arch foot is greatly affected by boundary conditions. According to the principle of reinforcement and load reduction and the results of model test, a mechanical calculation model of reinforced earth pressure is established, and the Rankine earth pressure theory is used. In this paper, the nonlinear earth pressure calculation formula of high fill roof with deformation layer and geogrid load reduction is put forward. It is proved by field test that the effectiveness, durability and the correctness of this method of calculation of load reduction effect of geogrid are proved. It has reference value for the design and construction of high-fill open hole and geogrid load-reducing structure.
【作者单位】：兰州交通大学;兰州工学院;
【基金】：长江学者和创新团队发展计划资助(IRT1139)
【分类号】：U452

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