贵阳某隐伏横向溶洞地基处理的稳定性分析

Stability Analysis on Foundation Treatment for a Transverse Karst Cave in Guiyang

岩溶地基的稳定性是地面建筑安全的重要保证。以贵州南明区某高层建筑的巨型溶洞处理为例,采用结构力学近似法和有限元分析法分析建筑荷载下溶洞顶板稳定性。通过数值模拟软件FLAC_(3D)建立不同填充材料及填充范围工况的计算模型,计算在建筑荷载下,不同填充材料和填充范围下溶洞顶板及地面的应变场和应力场特征。溶洞的填充材料分别是细石混凝土和碎石,填充范围包括全区域填充和建筑一侧的部分填充。对比分析了4种工况情况下,溶洞上覆地基变形的特征。与试测结果的对比表明:数值计算分析与现场监测数据吻合,复杂溶洞经处理后,在桩基荷载作用下地基稳定;细石混凝土的填充效果比碎石材料效果更佳,在保证建筑安全的基础上,部分填充的方案能为工程节省更多的成本。

The stability of karst foundation is an important guarantee for the safety of ground buildings.Taking an actual engineering of treatment for a giant karst cave under a high-rise building in Guizhou Province as an example,the stability for the roof subjected to building loads was analyzed used by the structural mechanics approximation method and finite element method.By the numerical simulation software FLAC_(3D),the calculation models of foundation with karst caves filled with different materials and ranges were constructed to calculate the characteristics of the strain field and stress field in the cave roof and ground under building loads.The materials filled in karst caves were fine aggregate concrete and crushed stone respectively,and the filling ranges included the whole void and the partial void in the side of the building.The deformation characteristics of overlying foundation in four working conditions were compared and analyzed.The results showed that the numerical analysis consonant with the actual monitoring data,and the treated foundation with complex karst cavities was stable under the action of pile loads,and the filling effect of fine aggregate concrete was better than that filled by gravel material.On the basis of ensuring the safety for the building,the partial filling scheme could save more cost for the project.