为研究红粘土地质条件下的PHC管桩的承载性能,以柳州某实际工程为案例,应用FLAC 3D软件进行数值建模,对实际工程静压PHC管桩的静载试验进行数值模拟,对比分析数值模拟和工程桩静载试验的结果,对红粘土地基PHC管桩的荷载传递规律和桩顶沉降规律进行数值模拟和研究分析.结果表明:FLAC3D数值模拟和静载试验的Q-S曲线相比,数值略小,曲线比较接近,基本趋势亦相同,数值模拟的结果能较好地反映PHC管桩的工作特性,模型参数的选择符合工程实际情况,PHC管桩单桩承载力设计值取值偏保守.PHC管桩的强度、桩长、桩端残余应力以及上覆红粘土的休止时间,都是影响桩体沉降的因素.在竖向荷载的作用下,桩身轴力由上往下衰减,变化较明显,为端承型摩擦桩的传递特性,地基沉降主要集中于桩侧和桩端接触面处.%Toresearchthe bearing properties of PHC pipe pile on red clay foundation,we study the case of a practi-cal engineering in Liuzhou. As the FLAC3Dsoftware is used to build the numerical model,the static load test of PHC pipe pile is simulated. The results of numerical simulation and static load test of engineering pile are com-pared. Numerical simulation and research analysis are conducted on the load transmission law and pile top settle-ment law of PHC pile on red clay foundation. The results show that: compared with the Q-S curve of FLAC3Dnu-merical simulation and static load test,the numerical value is slightly smaller,the curve is closer and the basic trend is the same. The results of numerical simulation can better reflect the working characteristics of PHC pile. The selection of model parameters is in line with the actual engineering situation,the design value of single pile bearing properties of PHC pipe pile is conservative.The strength of PHC pile,pile length,residual stress of pile end and rest time of red clay are all factors that influence the settlement of pile. Under the action of vertical load,the axial force of pile is attenuated from the top downwards,and the change is obvious,which is the transmission character-istic of the end bearing type friction pile. The settlement of foundation is mainly concentrated on the pile side and the pile end contact surface.
展开▼
