油田站场建构筑物基础下伏黄土洞穴地基稳定性数值分析

Numerical Analysis of Stability of Loess Caves Under Building and Structure Foundations of Oilfield Station

黄土暗穴常常影响油田站场的选址或对站场建构筑物安全构成威胁。为探究不同因素对黄土洞穴地基稳定性的影响,将洞穴概化为理想椭球状,利用ABAQUS程序建立油田站场典型建构筑物基础下伏黄土洞穴三维模型进行了大量的数值模拟分析。结果表明:当洞穴埋深越小、尺寸越大、与基础距离越近、高跨比越小,洞穴地基的稳定性越低,地基承载力越小,基础沉降越大;下伏洞穴地基极限承载力、洞穴安全埋深以及洞穴与基础的安全距离可通过基础沉降和地基土塑性区分布来确定。

Loess hidden caves often affect the site selection of oilfield stations or poses a threat to the safety of station buildings and structures.In order to investigate the effects of various factors on the stability of grounds with a loess cave,taking loess caves as an ideal ellipsoid oval and using the software ABAQUS,numerous numerical simulation analyses were performed by establishing the three-dimensional models of loess caves underlying the typical foundations of buildings and structures in an oilfield station.The results show that the shallower the burial depth of the cave under a foundation base and the bigger the size of the cave and the closer to the foundation the cave is as well as the less the ratio of height to span of the cave,the lower the stability of the ground with a loess cave,the lower the ground bearing capacity,and the greater the settlement of the foundation.The ultimate bearing capacity of grounds with a cave,the safe burial depth of caves as well as the safe distance of caves from a foundation can be determined by the settlement of the foundation and the distribution of plastic zones in soil.