水泥搅拌桩桩间距对桩身承载性能的影响  

Research on effect of pile spacing on pile bearing performance of cement mixing pile

作　　者：尹晓桐 黄勇 YIN Xiaotong;HUANG Yong(CMCU Engineering Co.,Ltd.,Chongqing 400041,China)

机构地区：[1]中机中联工程有限公司,重庆400041

出　　处：《工程建设》2024年第3期39-43,共5页Engineering Construction

摘　　要：为探究水泥搅拌桩桩间距对桩身承载性能的影响,以重庆市玉泉湖一路K1+435~K1+550路段水泥搅拌桩处置工程为背景,结合理论研究及数值模拟,探讨分析了不同桩间距布置条件下的水泥搅拌桩桩身侧摩阻力、竖向应力及加固区沉降变化情况。研究结果表明:1)水泥搅拌桩侧摩阻力中性点出现在埋深1/4桩长处,且随桩间距的增加,中性点位置下移;2)在桩间距从3倍桩径增大至5倍桩径的过程中,桩侧负摩阻力峰值由15.7 kPa增至18.3 kPa,增大了16.6%,而桩间距对正摩阻力峰值的影响较小;3)水泥搅拌桩桩身竖向应力沿埋深方向递减,当桩间距增大时,持力层顶部应力水平持续增加,地表及加固区沉降均随桩间距的增大而不断增大;4)桩间距3.3倍桩径的水泥搅拌桩复合路基承载力为456.68 kPa,处置效果良好。本文成果可为水泥搅拌桩在复合软弱路基处置工程中的应用提供一定的借鉴与参考。In order to explore the influence of cement mixing pile spacing on the pile bearing performance,the cement mixing pile disposal project of K1+435~K1+550 section located at Yuquanhu 1st road in Chongqing is taken as the background,theoretical research and numerical simulation are combined,and the lateral friction resistance,vertical stress and settlement changes of reinforcement area under different pile spacing conditions are discussed and analyzed.The results show that:1)The neutral point of the lateral friction resistance of the cement mixing pile appears at the length of the 1/4 pile of the buried depth,and the position of the neutral point moves down with the increase of the pile spacing;2)The peak value of the negative friction resistance on the pile side increases from 15.7 kPa to 18.3 kPa when the pile spacing increases from 3 times the pile diameter to 5 times the pile diameter,which is increased by 16.6%;3)The vertical stress of the cement mixing pile decreases along the buried depth direction,and when the pile spacing increases,the stress level at the top of the bearing layer continues to increase,and the settlement of the surface and reinforcement area increases with the increase of pile spacing;4)The bearing capacity of the composite subgrade of the cement mixing pile with a pile spacing of 3.3 times the pile diameter is 456.68 kPa,and the disposal effect is good.The results can provide certain references for the application of cement mixing piles in weak composite subgrade treatment projects.

关 键 词：水泥搅拌桩 桩间距 桩身承载性能 软弱复合路基 

分 类 号：TU473.1[建筑科学—结构工程]