竖井侧压力的计算方法及数值模拟

发布时间：2018-03-05 06:51

本文选题：竖井　切入点：侧压力　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：：土压力的计算问题是岩土工程领域中三大重要的研究课题之一,在曲面挡土墙结构得到的研究成果具有很好的应用价值。本文在库仑土压力理论的基础上对竖井等曲面结构的侧压力计算理论作了进一步研究。传统的极限平衡理论忽略了相邻微元体两侧的法向作用力,并运用的的是直线挡土墙理论进行研究的。对于竖井等圆弧形曲面结构物,相邻微元体两侧的法向作用力对土体的平衡有重要的影响。本文以库伦土压力理论和原方计算法为基础,考虑了竖井曲面形式和相邻微元体两侧的法向作用力对土压力计算的影响。选择三维微扇形单元土体,进行受力分析,由静力平衡条件,推导出了竖井侧压力计算的表达式。结合三个计算实例,每个竖井选取不同的半径和深度,结合数值模拟分析,得到了影响竖井侧压力的几个因素。通过和本文推导公式的计算结果对比,二者结果基本吻合,证明了本文推导公式的正确性。通过对比不同半径、不同深度、不同相对刚度下竖井的侧压力,得到以下结论： 1.由于竖井的曲面效应影响,使得竖井侧压力计算值比两种经典计算方法偏小。因此,对于曲面结构挡土墙,经典理论计算方法不够合理。 2.与常规土压力不同的是,竖井侧压力大小随着深度的增加,表现为非线性增大。 3.竖井侧压力与半径有关。随着半径增大而增大,最终趋于一稳定值。不同相对刚度对竖井侧压力影响不大。
[Abstract]:The calculation of earth pressure is one of the three important research topics in the field of geotechnical engineering. The research results obtained in curved retaining wall structure have good application value. Based on Coulomb earth pressure theory, the lateral pressure calculation theory of shaft and other curved structures is further studied in this paper. The traditional limit equilibrium theory ignores the normal forces on both sides of adjacent microelements, and applies the theory of linear retaining wall. The normal forces on both sides of adjacent microelements have an important effect on the balance of soil mass. This paper is based on the Coulomb theory of earth pressure and the original calculation method. Considering the influence of the surface form of shaft and the normal force on both sides of adjacent micro-element body on the calculation of earth pressure, the calculation expression of lateral pressure of shaft is derived by selecting three-dimensional micro-sector element soil mass and carrying out the force analysis by using the static equilibrium condition. Combined with three calculation examples, each shaft selected different radius and depth, combined with numerical simulation analysis, several factors affecting the lateral pressure of the shaft were obtained. By comparing the calculated results with the formula derived in this paper, the two results are basically in line with each other. It is proved that the formula is correct. By comparing the lateral pressure of the shaft with different radius, depth and relative stiffness, the following conclusions are obtained:. 1. Due to the influence of surface effect of shaft, the calculated value of lateral pressure of shaft is smaller than that of two classical methods. Therefore, the classical theoretical calculation method is not reasonable for curved surface retaining wall. 2. Different from the conventional earth pressure, the lateral pressure of the shaft increases with the depth of the shaft. 3. The lateral pressure of the shaft is related to the radius, which increases with the increase of radius, and eventually tends to a stable value. Different relative stiffness has little effect on the lateral pressure of the shaft.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U451;U455.8

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