大体积有压箱涵渗漏对土体力学性能影响分析

Analysis of the influence of leakage of large volume pressure box culvert on the mechanical properties of soil

大体积有压箱涵运行过程中极易发生渗漏问题,对周围环境产生不利的影响。如:渗漏水渗出地面影响耕地的使用、由于土体不均匀沉降导致箱涵及附近建(构)筑物遭到破坏等。为研究箱涵渗漏对周围土体位移场和应力场变化的影响,利用流固耦合方法进行了计算分析,研究了不同的渗漏位置、渗透系数及箱涵内水压力下发生渗漏后箱涵附近土体力学性能变化的发展规律。结果表明:渗漏位置在箱涵侧墙与底板相交处,渗漏造成的周围土体沉降最大,渗漏位置附近的有效应力减小;土层渗透系数发生变化时,渗漏位置所在土层的渗透系数增大使土体沉降更大,浸润面高度更高;箱涵的内水压力越大,渗漏后土体沉降幅度越大,土体的沉降范围也越大;渗漏后土体浸润线高度越高土体沉降越大,塑性应变越大。

Leakage is easy to occur in the operation of large-volume pressure box culvert,which has adverse effects on the surrounding environment.For example,water seepage affects the use of cultivated land,and the non-uniform settlement of soil leads to the destruction of box culvert and nearby structures.In order to study the influence of box culvert seepage on the displacement field and stress field of the surrounding soil,fluid-solid coupling method was used to calculate and analyze the development law of the mechanical properties of the soil around the box culvert after the leakage occurs under different leakage locations,permeability coefficients and water pressure.The analysis results show that the displacement settlement of soil around the leakage is the largest,and the effective stress around the leakage location decreases when the location of leakage was intersection of box culvert side wall and roof.After the proportion of soil permeability coefficient changes,the lifting height of soil mass at the bottom of the box culvert also increases,but the degree of soil uplift eventually reaches the limit.When the soil permeability coefficient changes in different proportions,the infiltration coefficient of the soil layer where the leakage was located increases,so that the soil settlement is larger and the height of the infiltration surface is higher.The larger the internal water pressure of the box culvert is,the larger the displacement settlement amplitude is and the larger the settlement range is.