Pile-anchor support in foundation pit in expansive soil regions puts forward higher requirements for anchors. By example of an expansive soil foundation pit in the eastern suburbs of Chengdu,comparative on-field tests on ultimate pullout force and creep-relaxation characteristics are carried out between under-reamed compression anchors and normal tension anchors to study the feasibility of pile-anchor support in the foundation pit. Test results show that under-reamed compression anchors present high bearing capacity and good deformation control,and creep and stress relaxation characteristics are better than normal tension anchors. Based on field test results,the anchor-pile support scheme by combining under-reamed compression anchors and support piles is adopted through scheme comparison to conduct the application study. The pullout tests of the anchors are conducted and anchor stress state is monitored in the application study. The horizontal displacements of foundation pit and the settlements of the surrounding buildings are monitored as well. The results show that the under-reamed compression anchor has good applicability in foundation pit engineering in Chengdu expansive soil regions. The research results can provide reference for the design of foundation pit support in similar project.
张敬一. 膨胀土地区承压扩体锚杆现场试验及应用研究[J]. 岩石力学与工程学报, 2018, 37(S2): 4367-4374.
ZHANG Jingyi. On-field test and application study of under-reamed compression anchors in expansive soil regions. , 2018, 37(S2): 4367-4374.
冯金良,赵振宏,赵 翔. “成都黏土”的成因、物源、时代及其古环境问题[J]. 山地学报,2014,32(5):513-525.(FENG Jinliang,ZHAO Zhenhong,ZHAO Xiang. The origin,provenance,age and climatic links of the Chengdu clay:a review[J]. Mountain Research,2014,32(5):513-525.(in Chinese))
[2]
龙 飞. 成都裂隙性黏土基坑土压力计算方法研究[硕士学位论文][D]. 成都:西南交通大学,2015.(LONG Fei. Research on the computational method of earth pressure for the excavations in fissured clay in Chengdu area[M. S. Thesis][D]. Chengdu:Southwest Jiaotong University,2015.(in Chinese))
[3]
李朝阳,谢 强,康景文. 成都某膨胀土基坑边坡失稳机理分析[J]. 建筑科学,2015,31(9):8-12.(LI Zhaoyang,XIE Qiang,KANG Jingwen. Instability mechanism analysis of an expansive soil excavationslope in Chengdu[J]. Building Science,2015,31(9):8-12.(in Chinese))
[4]
梁作显. 悬臂排桩支护膨胀土基坑边坡优化设计[硕士学位论文][D]. 成都:西南交通大学,2012.(LIANG Zuoxian. The study on cantilever pile optimal design of expansive soil foundation pit slope [M. S. Thesis][D]. Chengdu:Southwest Jiaotong University,2012.(in Chinese))
[5]
中华人民共和国国家标准编写组. GB 50112—2013 膨胀土地区建筑技术规范[S]. 北京:中国建筑工业出版社,2013.(The Professional Standards Compilation Group of People¢s Republic of China. GB 50112—2013 Technical code for buildings in expansive soil regions[S]. Beijing:China Architecture and Building Press,2013.(in Chinese))
[6]
中华人民共和国行业标准编写组. JGJ120:2012 建筑基坑支护技术规程[S]. 北京:中国建筑工业出版社,2013.(The Professional Standards Compilation Group of People¢s Republic of China. JGJ120:2012 Technical specification for retaining and protection of building foundation excavation[S]. Beijing:China Architecture and Building Press,2013.(in Chinese))
[7]
中华人民共和国行业标准编写组. JGJ/T 282:2012 高压喷射扩大头锚杆技术规程[S]. 北京:中国建筑工业出版社,2013.(The Professional Standards Compilation Group of People¢s Republic of China. JGJ/T282:2012 Technical specification for underreamed anchor by jet grouting[S]. Beijing:China Architecture and Building Press,2013.(in Chinese))
[8]
程良奎,张培文,王 帆. 岩土锚固工程的若干力学概念问题[J]. 岩石力学与工程学报,2015,34(4):668-682.(CHENG Liangkui,ZHANG Peiwen,WANG Fan. Several mechanical concepts for anchored structures in rock and soil[J]. Chinese Journal of Rock Mechanics and Engineering,2015,34(4):668-682.(in Chinese))
[9]
刘钟,郭 钢,张 义,等. 囊式扩体锚杆施工技术及工程应用[J].岩土工程学报,2014,36(增2):205-211.(LIU Zhong,GUO Gang,ZHANG Yi,et al. Construction technology and engineering application of capsule-type under-reamed ground anchor[J]. Chinese Journal of Geotechnical Engineering,2014,36(Supp.2):205-211.(in Chinese))
[10]
中华人民共和国协会标准编写组. CECS22:2005 岩土锚杆(索)技术规程[S]. 北京:中国计划出版社,2005.(The Professional StandardsCompilation Group of People¢s Republic of China. CECS22:2005 The technical specifications for ground anchor[S]. Beijing:China Planning Press,2005.(in Chinese))
[11]
KIM N K. Performance of tension and compression anchors in weathered soil[J]. Journal of Geotechnical and Geotechnical Engineering,2003,129(12):1 138-1 150.
[12]
中华人民共和国国家标准编写组. GB 50497:2009 建筑基坑工程监测技术规范[S]. 北京:中国计划出版社,2009.(The Professional Standards Compilation Group of People¢s Republic of China. GB 50497:2009 Technical code for monitoring of building excavation engineering[S]. Beijing:China Planning Press,2009.(in Chinese))