基于不同贯入速率砂土地基中静压敞口混凝土管桩试验研究  

Model test on jacked open-ended concrete pipe pile in sand under different penetration speeds

作　　者：寇海磊[1,2] 李旺 杨丹良 杨萌 马纯杰 刘阿森 KOU Hailei;LI Wang;YANG Danliang;YANG Meng;MA Chunjie;LIU Asen(College of Engineering,Ocean University of China,Qingdao 266100,China;Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone,Qingdao Technological University,Qingdao 266033,China;Weifang Architectural Design&Research Institute Co.,Ltd,Weifang 261000,China;School of Civil Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266100 [2]青岛理工大学蓝色经济区工程建设与安全协同创新中心,山东青岛266033 [3]潍坊市建筑设计研究院有限责任公司,山东潍坊261000 [4]天津大学建筑工程学院,天津300072

出　　处：《建筑结构学报》2020年第7期140-145,共6页Journal of Building Structures

基　　金：国家自然科学基金面上项目(51879246);山东省自然科学基金面上项目(ZR2019MEE056);中国海洋大学青年英才工程计划项目(841712014);国土资源部公益性行业科研专项(201511037)。

摘　　要：贯入速率对静压敞口混凝土管桩沉贯及承载力特性具有重要影响。通过砂土地基中静压敞口混凝土管桩室内模型试验,分别对不同贯入速率下模型桩土塞特性、压桩力及极限承载力变化进行研究。结果表明,模型桩贯入速率由2. 0 mm/min增大至3. 0、4. 0 mm/min时,土塞高度分别降低了12. 8%、27. 2%,土塞率降低幅值分别为12. 9%、27. 2%。不同贯入速率沉桩结束后,模型桩土塞增长率分别为35. 4%、23. 6%及19. 8%;相比于4. 0 mm/min贯入速率,贯入速率2. 0 mm/min及3. 0 mm/min下模型桩最终压桩力增长幅度分别为92. 6%及25. 1%,极限承载力增长幅值分别为77. 8%及4. 5%,这主要是由于贯入过程中土塞特性差异导致的内壁摩阻力不同所引起的。研究成果可为砂土地基中敞口混凝土管桩沉桩性状及极限承载力研究提供理论依据。Penetration speed plays an important role during and after pile installation. Based on model tests,the effect of penetration speed on soil plugging,jacking forces and ultimate bearing capacity of open-ended concrete pipe piles in sand were investigated. Test results indicate that the reduction of soil plug height are 12. 8% and 27. 2% respectively,when the penetration speed increases to 3. 0 mm/min and 4. 0 mm/min from 2. 0 mm/min. Meanwhile,the corresponding reduction values of plug length ratio( PLR) are 12. 9% and 27. 2%,respectively. The PLR values are 35. 4%,23. 6% and 19. 8% after installation under different penetration speeds. Compared with the penetration speed of 4. 0 mm/min,the final jacking forces under 2. 0 mm/min and 3. 0 mm/min are 92. 6% and 25. 1% larger,respectively,the ultimate bearing capacity are 77. 8% and 4. 5% larger,respectively. This can be explained by the difference in inter shaft resistance caused by different soil plugging. These findings are useful for the research on installation and ultimate bearing performance of open-ended concrete pipe piles jacked into sands.

关 键 词：开口混凝土管桩 贯入速率 模型试验 压桩力 土塞高度 极限承载力 

分 类 号：TU473.1[建筑科学—结构工程] TU317.1[建筑科学—土工工程]