邻近管线渗水条件下基坑开挖变形研究

Study on Deformation of Foundation Pit under the Condition of Water Seepage from the Adjacent Pipelines

黄土湿陷性会对基坑工程稳定性产生不利影响,因此研究增湿作用对基坑工程稳定性的影响显得尤为重要。基于Richards渗流理论和弹塑性本构模型,查阅资料引入土体力学参数和饱和度的量化关系,建立考虑增湿作用的基坑变形计算方法。通过以内撑式基坑为例分析增湿作用及变形控制影响因素对基坑开挖变形规律的影响。研究结果表明:由于增湿后的土体强度参数发生明显衰减,导致增湿后基坑变形显著增大;分析增湿后基坑变形受支护桩插入比、相邻建筑以及支撑数量的影响。

The collapsibility of loess will have an adverse impact on stability of foundation pit.Therefore,it is important to study the impact of wetting condition on stability of foundation pit.A method for calculating the deformation of foundation pit under considering wetting condition is established by using Richards seepage theory and elastoplastic constitutive model,introducing the quantitative relationship between soil mechanical parameters and saturation based on documentation.By taking foundation pit with inner supports as an example,it analyzes the effect of wetting and deformation control factors on the deformation law of foundation pit.The results show that due to the obvious attenuation of soil strength parameters after wetting,the deformation of foundation pit increases after wetting;the deformation of foundation pit after wetting is affected by the insertion ratio,adjacent buildings and the numbers of support.