软岩嵌岩桩单桩模型试验及承载特性研究

Model Experiment and Bearing Behavior Characteristic of Single Socketed Pile in Soft Rock

现场试验和室内模型试验是揭示软岩嵌岩桩承载机理的重要方法。由于软岩嵌岩桩桩径大,承载力高,现场试验成本随之增高,且可重复性有待商榷。故本文基于室内模型开展不同嵌岩深度、不同桩径及上覆压力的多组模型试验,对软岩嵌岩桩承载特性进行分析探讨。研究结果表明:采用水泥、石膏、砂、水和早强剂等材料模拟软岩方法可行,且在模型试验中取得良好效果;嵌岩深度增加、桩径增大,上覆压力提高,嵌岩桩其承载力明显提高;上覆压力对于软岩嵌岩桩嵌岩段的极限侧摩阻力影响较小。

Field tests and indoor model tests are the main methods to study bearing mechanism of socketed piles in soft rock.Because of the large pile diameter and high bearing capacity of socketed piles in soft rock,the costs of field test increase accordingly,and the repeatability remains to be discussed.Therefore,a series of model pile load tests based the indoor model have been carried out to investigate the effects of socketed depth,pile diameter and overburden pressure on the bearing behavior of socketed pile in soft rock.The results show that the synthetic soft rock made of cement,gypsum powder,river sand,water and concrete hardening accelerator is presented for model tests is feasible and with good results.The socketed pile capacity increases obviously with increasing socketed depth,pile diameter and overburden pressure.The overburden pressure shows litter influence on the ultimate shaft resistance of model pile.