大直径劲性搅拌桩承载力试验研究  

Experimental study on bearing capacity of large diameter reinforced mixing pile

作　　者：赵子江 陈强[2] 别社安[1] ZHAO Zi-jiang;CHEN Qiang;BIE She-an(School of Civil Engineering,Tianjin University,Tianjin 300350,China;Tianjin Port&Channel Engineering Co.,Ltd.,Tianjin 300457,China)

机构地区：[1]天津大学建筑工程学院,天津300350 [2]天津港航工程有限公司,天津300457

出　　处：《中国港湾建设》2020年第3期20-24,38,共6页China Harbour Engineering

摘　　要：劲性搅拌桩是一种将PHC管桩插入水泥土中形成协同受力的桩型。在天津市汉沽区某工业园区场地内进行了大直径等长芯劲性搅拌桩单桩竖向承载力试验,并和相同直径灌注桩做了对比。试验结果表明,劲性搅拌桩成桩质量好,水泥土取芯单轴抗压强度高,可以为管桩-水泥土内界面提供足够的抗剪强度。大直径劲性搅拌桩极限承载力、单桩总侧阻力、端承阻力和同直径灌注桩相比均有大幅度提升,短劲性搅拌桩的端承比例更大且端阻发挥的时机更早。和同直径的灌注桩比,劲性搅拌桩提供相同的承载力所需的桩身长度大幅度减少,降低单位承载力造价。The reinforced mixing pile is featuring that a PHC pipe is inserted into the cement soil to form a cooperative bearing mechanism.In the site of an industrial park in Hangu District,Tianjin,the vertical bearing capacity test of the large-diameter long equal core-reinforced mixing piles was carried out,and comparative trial for the filling piles with the same diameter as reinforced piles was performed too.Test results show that,the reinforced mixing pile has favorable quality,and high uniaxial compressive strength of samples of cement-soil core can provide sufficient shear strength for the pipe-cement interface.Compared with the same diameter cast-in-place pile,the ultimate bearing capacity of the large-diameter reinforced pile,the total lateral resistance of the single pile,and the end bearing resistance are all remarkably improved.The end bearing ratio of the reinforced mixing pile with shorter length is superior and the end resistance take effect in a earlier stage.The length of the pile body required for the reinforced pile to provide the same bearing capacity is greatly reduced,and the cost of unit bearing capacity is reduced.

关 键 词：劲性搅拌桩 PHC管桩 侧阻调整系数 端承比 桩身轴力 水泥土抗压强度 

分 类 号：U655.544.1[交通运输工程—港口、海岸及近海工程] TU43[交通运输工程—船舶与海洋工程]