摘要
为计算岩溶区桩基的极限承载力,提出一个符合工程实际情况的简化分析模型,充分考虑了桩与溶洞之间距离对桩基承载力的影响。基于极限分析上限法,提出了相应的假定破坏模式,并采用三角形刚性块体对破坏模式进行离散,计算得到外力功率和内能耗散率。以桩端极限承载力作为目标函数,将该问题转化为数学优化模型,并利用MATLAB对数学优化模型求解。将本文计算结果与有限元极限分析法所得结果进行对比,验证了本文方法的正确性。最后,分析了材料参数和几何参数对桩基极限承载力的影响,参数分析表明:随着桩与溶洞距离不断增大,溶洞对桩端承载力的影响越来越小,当桩与溶洞距离超过某一定值时,桩端极限承载力将不受溶洞的影响。
To calculate the ultimate bearing capacity of pile foundation in karst areas,a simplified analysis model is proposed,which fully considers the influence of the distance between the pile and the karst cave on the bearing capacity of pile foundation.Based on the upper bound limit analysis,the corresponding assumed failure mode is proposed.The triangular rigid block is used to discrete the failure mode,and the external force power and internal energy dissipation rate are calculated.Taking the ultimate bearing capacity of pile foundation as the objective function,the problem is transformed into a mathematical optimization model,which is solved by the MATLAB software.To verify the correctness of the present method,the calculation results of the present analysis are compared with those from the upper bound finite element limit analysis.Finally,the influence of material parameters and geometric parameters on the ultimate bearing capacity of pile foundation is analyzed.The parameter analysis shows that with the increasing distance between the pile and the karst cave,the influence of the karst cave on the bearing capacity of the pile tip becomes smaller and smaller.When the distance between the pile and the karst cave exceeds a certain value,the ultimate bearing capacity of the pile tip will not be affected by the karst cave.
作者
张红卫
Zhang Hongwei(China Railway 22nd Bureau Group Fifth Engineering Co.,Ltd.,Chongqing 400000,P.R.China)
出处
《地下空间与工程学报》
CSCD
北大核心
2024年第4期1266-1274,共9页
Chinese Journal of Underground Space and Engineering
基金
广东省自然科学基金(2023A1515011684)。
关键词
桩基础
溶洞
桩端
极限承载力
上限分析法
pile foundation
karst cave
pile tip
ultimate bearing capacity
upper bound limit analysis
