岩溶区桩基承载特性研究综述

Review of Research Progress on Bearing Characteristics and Key Disposal Techniques of Pile Foundation in Karst Area

在岩溶区进行桩基施工时,应尽可能地避开溶洞,但不可避开的情况也普遍存在,因此岩溶区桩基承载特性研究是桩基发展过程中必须要面对的问题。从理论研究、物理实验、数值模拟3个方面对岩溶区桩基承载特性研究现状进行了分析,得到如下结论:现有承载力计算公式存在影响因素考虑不全的情况,后续理论研究应考虑多因素协同影响下单桩极限承载力计算公式推导。物理模型试验的变量较为单一,试验过程中常常忽略水对桩基承载特性的影响,后续研究应当重点考虑地下水及多因素的协同作用。原位实验开展较少,检测获得数据准确性有待提高,后续应开展更多的原位实验、现场破坏实验以获得更全面的桩基承载特性实验数据。数值模拟研究中溶洞模型的建立大多采用长方体、正方体、椭球体、球体等标准尺寸,这与实际地层溶洞三维几何尺寸不符,真实的溶洞几何模型的建立是未来重点的发展方向。

Karst caves should be avoided as far as possible during pile foundation construction,but sometimes it is unavoidable.Therefore,research on the bearing characteristics of pile foundations in karst areas is a problem that must be faced.The current status of research on the bearing characteristics of pile foundations in karst areas from three aspects:theoretical research,physical experiments,and numerical simulation was analyzed.The following conclusion was drawn.The existing bearing capacity calculation formulas have insufficient consideration of influencing factors,and subsequent theoretical research should consider the derivation of single pile ultimate bearing capacity calculation formulas under the synergistic influence of multiple factors.The variables in physical model tests are relatively single,and the influence of water on the bearing characteristics of pile foundations is often ignored during the testing process.Subsequent research should focus on the synergistic effect of groundwater and multiple factors.There are few in-situ experiments conducted,and the accuracy of the data obtained through detection needs to be improved.In the future,more in-situ experiments and in-site damage experiments should be carried out to obtain more comprehensive experimental data on the bearing characteristics of pile foundations.Most of the cave models are built with standard size in numerical simulation,which is inconsistent with the three-dimensional geometric size of the actual stratum cave.The establishment of a more realistic Geometric modeling of the cave is a key development direction in the future.