深厚覆盖层振冲碎石桩施工中的孔隙水应力分析

Analysis of Pore Water Stress in Vibroflotation Pile Construction in Deep Overburden Layer

硬梁包水电站首部枢纽工程覆盖层深厚,地质条件复杂,多为含孤(漂)、块(卵)碎砾石层。工程中采用的振冲碎石桩施工属于超常规振冲成桩工艺,故难以精确估计其在施工过程中对地层产生的影响。因此,对超常规振冲碎石桩施工过程进行孔隙水应力有限元分析是此次研究的关键点。阐述了使用Abaqus有限元软件二维模拟振冲碎石桩在施工过程中对地层产生的影响,并对地层之间产生的孔隙水应力以及位移进行了分析。通过对模拟结果进行分析,最终得出振冲碎石桩施工对地层产生的影响在合理的范围内,进而保证了振冲碎石桩的正常施工和安全。

The overburden of the headworks of the Yingliangbao Hydropower Station is thick and the geological conditions are complex,mostly composed of boulders(floats),blocks(pebbles)and gravels.The construction of vibro-crushed stone pile belongs to the super standard vibro-forming process,so it is difficult to accurately estimate the impact on the stratum during construction.The key point of this paper is how to carry on the finite element analysis of pore water stress in the construction process of unconventional vibroflotation pile.In this paper,Abaqus finite element software is used to simulate the influence of vibroflotation pile on the formation during construction,and the pore water pressure and displacement generated by the formation are analyzed emphatically.Through the analysis of the simulation results,it is concluded that the influence of vibroflotation pile construction on the stratum is within a reasonable range,which ensures the normal construction of vibroflotation gravel pile and the overall construction safety.