上拔、水平联合荷载对桩基承载性能影响的现场试验及数值模拟

通常桩基受力作用分别确定上拔、水平2个方向的承载力,不考虑其相互影响,不能准确反映桩基的真实受力状况.为研究桩基上拔、水平荷载的耦合作用对桩基上拔、水平向承载性能的影响,开展了大型现场试验及数值模拟研究.研究结果表明:上拔、水平联合荷载对桩基承载性能的影响与上拔、水平向荷载的比例有较大关系,当该比例小于2时,联合荷载作...

Experimental and Numerical Investigation of the Effect of Uplift and Lateral Combined Loading on the Bearing Capacity of Piles

The uplift and lateral bearing capacity of piles are commonly determined independently irregardless of their interactions in practice;however,this does not reflect their reality.The bearing capacity of piles under uplift and lateral combined loading was studied through field experiments and numerical simulation.The results show that the influence of the combined loading on the bearing capacity of piles is correlated closely related to the ratio of uplift to lateral load.In this study,the combined loading has little influence on the lateral bearing capacity when the ratio is less than 2;however,the lateral bearing capacity is obviously weakened when the ratio is greater than 2 and the degree of weakening increases with the increase in ratio.The uplift load displacement curve under the combined loading coincides with that under the uplift load.However,when the loading ratio is relatively small,the piles reach the failure standard earlier in the lateral direction,which leads to the failure of fully exerting the uplift bearing capacity.The lateral bearing capacity is weakened under the combined loading because the pile drives the soil around it to pull up in unison,which leads to a decrease in the proportion coefficient of soil resistance and the acceleration of the pile bending moment.Under the combined loading,the vertical earth pressure on the compression side increases due to the compaction of soil and the pressure on the tensile side decreases due to the separation of pile and soil for the upper part due to the lateral load.However,the vertical earth pressure on the lower part of the pile shows the opposite trend due to the rigid rotation of the pile.The soil cracks in the failure area are distributed in a fan shape under combined loading,where range,distribution,and failure mechanism are significantly different from those under uplift and lateral load.The influence of combined loading on the bearing capacity of piles is objective and cannot be ignored.