条形基础作用下粗粒土地基沉降计算改进方法

Improvement method of coarse-grained subgrade settlement calculation under strip foundation

目前,工程中普遍采用规范法和分层总和法计算粗粒土地基沉降量,然而,上述方法是基于连续介质理论建立的,与工程实际存在差异,其结果也存在一定误差。针对这些不足,考虑粗粒土地基散体介质特征,建立了求解条形均布荷载作用下粗粒土地基附加应力的解析方法;基于孔隙介质力学理论,建立了变形力学参数随地基变形呈非线性变化的参数计算模型;在此基础上,提出了适用于粗粒土地基沉降量计算的分层总和改进方法。分别采用规范法、分层总和法和提出的改进方法计算某实例沉降量,并与试验监测值进行对比分析。结果表明,建立的条形基础作用下粗粒土地基沉降计算改进方法更接近试验监测值,表明方法具有合理性和可行性。

At present,the standard method and the layerwise summation method are generally used to calculate coarse-grained subgrade settlement in engineering.However,these methods are established based on the continuum theory,which are not consistent with engineering facts,and the results also have some deviations.Therefore,in this paper,considering the granular medium characteristics of coarse-grain soils,the additional stress analysis method of coarse-grain subgrade under strip uniform loads is established,and the nonlinear model of deformation mechanics parameters changed with subgrade deformation is established based on the mechanics theory of pore medium.On this basis,an improved layerwise summation method is proposed,which is applied to calculate coarse-grained subgrade settlement.Finally,the settlements of a case are calculated respectively by the standard method,the layerwise summation method and this improved method,and are compared with test monitoring result.The results show that the calculation result of this improved method of coarse-grained subgrade under strip foundation is closer to test monitoring result.The reasonability and feasibility of this improvement method are verified.