深圳光汇油库边坡稳定性分析及工程治理

 针对深圳光汇油库边坡由于连续强降雨导致的滑坡，分析该滑坡形成的原因和工程治理方案。现场勘查结果表明，滑动面处于顺坡向陡倾角的强～中风化接触面上，在强降雨条件下，部分下渗的降雨在岩土分界面上汇流，渗流强度加大，黏性颗粒大量流蚀，致使黏聚力值急剧下降，削弱岩土体的整体强度并导致滑坡的产生。根据该边坡的滑坡体结构特征反算滑动面的强度指标，结果表明黏聚力在饱水状态后的大幅度衰减与预先的分析是吻合的。在保持岩土参数不变的情况下，讨论软弱面坡度变化对稳定性的影响规律，认为二者之间并非呈单调变化的关系。考虑到坡脚的大型油罐和坡顶高压电塔的破坏后果很严重，采用抗滑桩加锚索的分级支护体系并基于计算分析确定支护参数。监测结果证明在后续强降雨条件下变形稳定，治理效果良好。上述分析和治理方法为类似强降雨条件下高危边坡的工程治理提供参考经验。

STABILITY ANALYSIS AND TREATMENT OF GUANGHUI OIL DEPOT SLOPE IN SHENZHEN

A serious landslide occurred in a slope in Shenzhen due to the continuous rainstorms. The landslide generation mechanism is studied and the treatment scheme is discussed accordingly. Based on the investigation information,the slip surface is found in the contact interface between highly and medium- decomposed marble. The contact materials have become saturated due to rainwater infiltration. And most cohesive particles are washed away by the infiltrated rainwater flow. The serious lost of cohesion,thereby,has weakened strength of the entire slope body and caused a landslide. The numerical model is established for back analysis according to the slope characteristics and the compution values of strength parameters have also confirmed the cohesion reduction due to rainwater infiltration. In addition,discussions are conducted on the influence from different contact interface angles to evaluate the slope stability. The correlation between the contact interface angle and the calculated factor of safety do not tend to be monotonous,which would be an important factor affecting the slope stability. The slide-resistant piles with anchors are applied as the new reinforcement design to prevent the slope failure in consideration of the importance of oil tanks and power transmission tower adjacent to the slope. The information monitored after several heavy rainstorms shows that the slope deformation has been well controlled. It is approved that stability of slope has been improved and the landslide is well treated. Some experiences from this project can be referred for slopes stability analysis and treatment design under similar rainstorm conditions.