|Table of Contents|

Drawing Field Test Study on Built-in Section Steel of Foundation Pit Grouting Micro-pile in Loess Area(PDF)

《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]

Issue:
2022年01期
Page:
116-124
Research Field:
基础工程
Publishing date:

Info

Title:
Drawing Field Test Study on Built-in Section Steel of Foundation Pit Grouting Micro-pile in Loess Area
Author(s):
SONG Fei1;  AI Yu-hao1;  ZHANG Bin2
(1. School of Highway, Chang'an University, Xi'an 710064, Shaanxi, China; 2.China Jikan Research Institute of Engineering Investigations and Design Co., Ltd., Xi'an 710043, Shaanxi, China)
Keywords:
loess area;  grouting micro-pile;  drawing field test;  section steel
PACS:
TU317
DOI:
10.19815/j.jace.2021.09033
Abstract:
In order to study the recovery technology of built-in section steel of cement-soil grouting micro-pile in loess area, the drawing field test of section steel was carried out. The triaxial compression tests of cement loess stones were carried out by using GDS triaxial apparatus, and the influence of cement mixing ratio on the strength of cement loess was analyzed. Based on the self-developed built-in section steel puller, the drawing field test of the section steel inside cement loess grouting micro-pile was carried out. The variation law of the drawing force, as well as the distribution law of the axial force and shear stress on the section steel were analyzed under the influence of cement mixing ratio and whether the section steel was coated with antifriction agent. The results show that the stress-strain curve of cement loess stone is strain softening type, and the deviatoric stress firstly increases and then decreases with the increase of strain, and finally tends to be stable. The curve can be divided into four stages, including linear elastic stage, yield stage, post-peak failure stage and residual strength stage. The section steel drawing process can be divided into four stages, including slow slip stage, fast slip stage, failure stage and horizontal stage. The ultimate drawing load of the built-in section steel in the grouting micro-pile increases linearly with the increase of cement mixing ratio, and there is residual load. Whether the section steel is coated with antifriction agent has an effect on the ultimate load and residual load of drawing. The ultimate load of section steel coated with antifriction agent is about 49% of that of steel without antifriction agent.

References:

[1] LEE T H,IM J C,KIM C,et al.An Experimental Study for Reinforcing the Ground Underneath a Footing Using Micropiles[J].Geotechnical Testing Journal,2018,41(4):648-663.
[2]BORTHAKUR N,DEY A K.Experimental Investigation on Load Carrying Capacity of Micropiles in Soft Clay[J].Arabian Journal for Science and Engineering,2018,43(4):1969-1981.
[3]蔡 强,石胜伟,韩新强,等.两种距径比下微型组合抗滑桩物理模型试验[J].长江科学院院报,2015,32(11):66-70,77.
CAI Qiang,SHI Sheng-wei,HAN Xin-qiang,et al.Physical Model Test of Micro-pile Composite Structure Under Two Ratios of Spacing to Diameter[J].Journal of Yangtze River Scientific Research Institute,2015,32(11):66-70,77.
[4]冯 君,周德培,江 南,等.微型桩体系加固顺层岩质边坡的内力计算模式[J].岩石力学与工程学报,2006,25(2):284-288.
FENG Jun,ZHOU De-pei,JIANG Nan,et al.A Model for Calculation of Internal Force of Micropile System to Reinforce Bedding Rock Slope[J].Chinese Journal of Rock Mechanics and Engineering,2006,25(2):284-288.
[5]黄 新,周国钧.水泥加固土硬化机理初探[J].岩土工程学报,1994,16(1):62-68.
HUANG Xin,ZHOU Guo-jun.Hardening Mechanism of Cement-stabilized Soil[J].Chinese Journal of Geotechnical Engineering,1994,16(1):62-68.
[6]谭罗荣.对“水泥加固土硬化机理初探”一文的讨论[J].岩土工程学报,1995,17(6):129-130.
TAN Luo-rong.Discussion on “Hardening Mechanism of Cement-stabilized Soil”[J].Chinese Journal of Geotechnical Engineering,1995,17(6):129-130.
[7]谷天峰,孙忠弟,骆凤涛,等.水泥-黄土注浆充填材料的试验研究[J].工程地质学报,2014,22(1):98-105.
GU Tian-feng,SUN Zhong-di,LUO Feng-tao,et al.Experimental Research on Loess Grouting Material for Coal Gob Filling[J].Journal of Engineering Geology,2014,22(1):98-105.
[8]俞永华,杨晓华.水泥黄土力学特性试验[J].长安大学学报(自然科学版),2003,23(6):29-32.
YU Yong-hua,YANG Xiao-hua.Experiments of Mechanic Property of Cement-loess[J].Journal of Chang'an University(Natural Science Edition),2003,23(6):29-32.
[9]张冠军,徐永福,傅德明.SMW工法型钢起拔试验研究及应用[J].岩石力学与工程学报,2002,21(3):444-448.
ZHANG Guan-jun,XU Yong-fu,FU De-ming.Testing Study and Application of Shape Steel Pullout in SMW Construction Method[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(3):444-448.
[10]李志伟.SMW工法型钢起拔力有限元分析[D].天津:天津大学,2008.
LI Zhi-wei.Finite Element Analysis of Pull-out Force of Shape Steel in SMW Engineering Method[D].Tianjin:Tianjin University,2008.
[11]李玉莹.黄土地区基坑注浆微型桩内置型钢回收的室内试验研究[D].西安:长安大学,2019.
LI Yu-ying.Laboratory Study on Steel Recycling of Grout Micro-pile in Loess Foundation Pit[D].Xi'an:Chang'an University,2019.
[12]周燕晓,黄 新,麻志刚.型钢水泥土构件界面粘结应力试验研究[J].路基工程,2010(4):165-167.
ZHOU Yan-xiao,HUANG Xin,MA Zhi-gang.Experimental Study on Bond Stress of Profile Bars Reinforced Cement Soil Component Interface[J].Subgrade Engineering,2010(4):165-167.
[13]顾士坦,郭 英,任振群,等.基坑SMW工法型钢起拔力的工程实测分析[J].四川建筑科学研究,2011,37(4):133-135,159.
GU Shi-tan,GUO Ying,REN Zhen-qun,et al.Engineering Actual Measurement Analysis of Shaped Steel Pull-out Force of SMW Engineering Method in Foundation Pits[J].Sichuan Building Science,2011,37(4):133-135,159.
[14]《地基处理手册》编写委员会.地基处理手册[M].2版.北京:中国建筑工业出版社,2000.
Foundation Treatment Manual Preparation Committee.Foundation Treatment Manual[M].2nd ed.Beijing:China Architecture & Building Press,2000.
[15]孔德志,冯娇伟,宋艳香.劲性水泥土桩连续墙的工作机理分析[J].岩土工程学报,2011,33(增2):43-46.
KONG De-zhi,FENG Jiao-wei,SONG Yan-xiang.Working Mechanism of Reinforced Soil-cement Mixing Wall[J].Chinese Journal of Geotechnical Engineering,2011,33(S2):43-46.
[16]黄 浩.水泥土室内试验及水泥土搅拌桩复合地基沉降研究[D].赣州:江西理工大学,2009.
HUANG Hao.Laboratory Test of Soil-cement and Settlement Study of Composite Foundation with Soil-cement Mixing Pile[D].Ganzhou:Jiangxi University of Science and Technology,2009.

Memo

Memo:
-
Last Update: 2021-02-10