CAJ | 학술논문

扩底楔形桩是一种可以有效发挥桩侧摩阻力和桩端阻力、降低负摩阻力影响的新型纵向变截面桩；然而针对其沉桩施工过程中的挤土效应、沉桩阻力等研究则相对较少。基于PFC数值分析软件，建立扩底楔形桩和等体积混凝土用量的常规等截面桩的沉桩施工过程模拟数值模型；通过与等截面桩沉桩模型试验和圆孔扩张理论计算结果的对比分析，验证了本文所建立的数值分析模型的准确性和可靠性；对比分析扩底楔形桩和等截面桩沉桩过程中桩周土体位移场、应力场以及沉桩阻力等变化规律。研究结果表明：沉桩过程中桩端阻力值的大小，不仅与横截面面积有关，而且与桩侧界面形式有关；本文数值模型情况下，扩底楔形桩静压沉桩施工桩端阻力、桩侧摩阻力和整体沉桩阻力分别是等截面桩的1．8，1．1和1．5倍。
확저설형장시일충가이유효발휘장측마조력화장단조력、강저부마조력영향적신형종향변절면장；연이침대기침장시공과정중적제토효응、침장조력등연구칙상대교소。기우PFC수치분석연건，건립확저설형장화등체적혼응토용량적상규등절면장적침장시공과정모의수치모형；통과여등절면장침장모형시험화원공확장이론계산결과적대비분석，험증료본문소건립적수치분석모형적준학성화가고성；대비분석확저설형장화등절면장침장과정중장주토체위이장、응력장이급침장조력등변화규률。연구결과표명：침장과정중장단조력치적대소，불부여횡절면면적유관，이차여장측계면형식유관；본문수치모형정황하，확저설형장정압침장시공장단조력、장측마조력화정체침장조력분별시등절면장적1．8，1．1화1．5배。
Belled wedge pile,which can improve the friction of pile shaft and tip resistance,and reduce negative skin friction effect,is one of variable cross-section piles.However,the analysis is seldom investigated concern-ing the pilling effect or pilling resistance characterizes on pile driving process.Based on PFC numerical simula-tion software,numerical models on pile driving process of belled wedge pile and traditional equal section pile with the same concrete usage were built.The accuracy and reliability of variable pile driving numerical models were verified by comparing with equal section pile driving model test results and the ones with cavity expansion theory.Then,the displacement field,stress field,and pile driving resistance were comprehensively discussed and analyzed.The results show that pile driving tip resistance is not only influenced by cross-section areas,but also influenced by form of pile side.The results also demonstrate that the pile driving tip resistance,pile shaft and total resistance of belled wedge pile are equal to 1 .8,1 .1 and 1 .5 times of those with equal section pile,re-spectively.