洪水冲刷浸泡联合作用下村镇建筑地基承载性能劣化机理研究

STUDY ON THE BEARING CAPACITY DEGRADATION MECHANISM OF THE VILLAGE BUILDING FOUNDATION UNDER THE COUPLING EFFECT OF FLOOD EROSION AND IMMERSION

洪水作用下地基承载性能劣化问题是影响山区村镇建筑安全的主要因素之一,也是乡村振兴战略中建设生态宜居的居民生活环境所面临的主要威胁。现有研究大多针对洪水浸泡下的地基承载性能劣化过程,而洪水冲刷及其与浸泡作用的联合影响还有待进一步研究。对此,本文围绕洪水冲刷浸泡联合作用下村镇建筑地基承载性能的复杂劣化过程开展研究,在二维浅水方程对洪水动力过程模拟基础上,构建考虑洪水流速垂向非线性分布律的侵蚀模型,进而对洪水作用下的地基土体冲刷深度进行计算。同时,综合考虑洪水浸泡后地基土力学的折减强度,采用有限元方法对洪水冲刷、浸泡下的地基承载力进行对比。典型案例分析表明,洪水冲刷浸泡联合作用下村镇建筑地基承载力下降47.88%,且洪水冲刷对地基承载力的劣化作用略强于洪水浸泡作用。

Bearing capacity degradation of foundation under the effect of flood is one of the major reasons responsible for the collapse and damage of village buildings.It is also one of the major threats to the ecologically livable living environment for the residents in the rural revitalization strategy.Up to date,most the existing studies have focused on the flood immersion and its impact to the degradation processes of the bearing performance,while the flood entrainment and erosion effect,as well as its coupling effect with the immersion need to be further studied.In this paper,we focus on the complex degradation process of the bearing performance of the village building foundation under the coupling effect of flood erosion and immersion,and then calculate the relevant erosion depth of the foundation.Meanwhile,considering the reduction of the mechanical strength of the foundation soil after the flood immersion,the finite element method is used to compare the bearing capacity of the foundation under flood erosion and immersion.Results show that under the coupling effect of flood erosion and immersion,the bearing capacity of village building foundations drops by 47.88%,wherein the degradation effect of flood erosion on the bearing capacity of foundations is slightly stronger than that of flood immersion.