CAJ | 학술논문

基坑开挖卸荷导致工程桩桩侧极限阻力降低。建立单桩模型，用 Mindlin 应力解考虑开挖引起的竖向有效应力变化，分别计算开挖前后的桩侧极限阻力。通过某工程案例，将理论结果与其他结果相对比。最后分析了桩侧阻力降低系数随基坑开挖深度、边长、长宽比及桩长的变化规律。结果表明：桩侧阻力降低系数随开挖深度增加先减小而后缓慢增大，存在谷值临界深度，随开挖边长、长宽比增加先减小而后趋于稳定；增加桩长导致桩侧阻力降低系数增大。
기갱개알사하도치공정장장측겁한조력강저。건립단장모형，용 Mindlin 응력해고필개알인기적수향유효응력변화，분별계산개알전후적장측겁한조력。통과모공정안례，장이론결과여기타결과상대비。최후분석료장측조력강저계수수기갱개알심도、변장、장관비급장장적변화규률。결과표명：장측조력강저계수수개알심도증가선감소이후완만증대，존재곡치림계심도，수개알변장、장관비증가선감소이후추우은정；증가장장도치장측조력강저계수증대。
The effect of excavation-related unloading on the underlying soil will reduce the ultimate pile shaft resistance.In this study,Mindlin's stress solution was used to allow for the variation of vertical ef-fective stresses induced by excavation around a single pile.The ultimate resistances of the pile shaft before and after the excavation were calculated.The results of theoretical calculation were compared with others through a case study.Furthermore,the variations of reduction factors for shaft resistance with excavation depth,excavation length,ratio of length to width and pile length were analyzed.The results showed that reduction factors for shaft resistance decreased firstly and then increased with the increase of excavation depth,and it decreased first and then tended to be stable with the increase of excavation length and ratio of length to width.With the increase of pile length,the reduction factors for shaft resistance increased.