摘要
考虑人工挖孔桩施工过程演化影响和护壁与桩芯作为竖向叠合受力构件,依据青岛胶东国际机场人工挖孔桩载荷试验数据,分析探讨了大直径嵌岩桩竖向载荷传递特性。分析表明,桩孔开挖卸土对上部填土、全风化岩扰动明显,而对下部强风化岩、中风化岩扰动较小。护壁与桩芯为竖向受力叠合构件,桩在较大竖向载荷下,上部护壁在分节处会开裂。在护壁端下继续开挖,会对护壁端及周边岩体产生扰动,进行护壁未至桩底的“悬挂式”护壁端阻力计算时应考虑实际开挖的影响。同时桩嵌岩深度为1.92D~3.15D(D为桩直径)时,桩端阻力占比为10.5%~31.5%,表现出摩擦桩特性。桩嵌岩深度调至1.0D~1.5D,桩端阻力占加载量比例可至38.2%~76.1%,使桩受力更为合理。
Based on the data of file load test of Qingdao Jiaodong International Airport,vertical load transfer characteristics of the manual digging large-diameter rock-embedded pile under the influence of construction evolution and retaining wall as superimposed components is analyzed and discussed.The analysis shows that the excavation and unloading of pile holes has obvious disturbances to the upper soil and fully weathering rock layers,while the disturbance to the lower strong weathered rocks and medium-weathered rock layers is small.The pile is under a large vertical load,the upper retaining wall will crack at the junction section.Continuing to excavate the weathered rock under the retaining wall will disturb the surrounding rock mass.The influence of actual excavation should be considered,when we calculate the end resistance of the“hanging”retaining wall which does not reach the bottom of the pile.The depth of rock embedding of the pile was 1.92D~3.15D(D is the pile diameter),and the end resistance accounted for 10.5%~31.5%,which shows the characteristics of friction pile.The depth of rock embedding is adjusted to 1.0D~1.5D,and the proportion of pile end resistance to loading capacity can be 38.2%~76.1%,and piles can work more reasonable.
作者
张军舰
隋倩倩
郭幔
殷坤宇
ZHANG Junjian;SUI Qianqian;GUO Man;YIN Kunyu(Geotechnical Technology Co.,Ltd.,Hangzhou 311401,China;Geotechnical Investigation and Surveying Research Institute,Qingdao 266032,Shandong,China;Qingdao Geotechnical Foundation Engineering Company,Qingdao 266032,Shandong,China;Qingdao Binhai Investigation and Surveying Co.,Ltd.,Qingdao 266071,Shandong,China)
出处
《力学与实践》
北大核心
2023年第4期765-776,共12页
Mechanics in Engineering
关键词
大直径嵌岩桩
挖孔桩护壁
竖向载荷传递特性
现场载荷试验
叠合构件
large-diameter socket pile
retaining wall
vertical load transfer characteristics
field test
superimposed components
