摘要
结合成都东郊膨胀土地区一深基坑,介绍微型钢管桩复合土钉墙的设计思路及应用情况。采用多种手段对基坑变形与支护构件内力进行监测,测得了土钉轴力、微型钢管桩弯矩与基坑水平位移、沉降值在各个开挖阶段随时间及空间的分布规律并实现了信息化施工,在基坑出现了较大变形时及时进行坡脚反压与加固,保证了边坡整体稳定性。根据对监测数据的分析及实际支护效果表明:"水"与初期开挖支护不及时是基坑整体变形较大的主要原因;土钉轴力发挥较为充分,为主要的受力构件,设计的土钉长度偏短;微型钢管桩受力较小,对基坑变形的控制作用有限,超前支护效果欠佳。取得的经验对成都地区类似工程具有借鉴意义。实测的监测数据有助于复合土钉墙理论研究。
Combined with a deep excavation project in expansive soil areas of Chengdu eastern suburb,the design and application of micro-steel pipe piles composite soil nailing wall are introduced. The changing rules of internal force with time and space are obtained by a variety of means,including force of soil nails,bending moment of micro-steel pipe piles,horizontal displacement and sedimentation value of foundation pit in different excavation stages. Informational construction is realized. Toed back pressure and reinforcement in the foundation pit is performed on time when it has a large deformation,which guaranteed the overall stability of slope. The actual effect of support and the analysis of monitoring data show that： Water and the delay of initial support are the main causes of foundation pit＇s large deformation; Soil nails are the main stress components for their axial force are brought into fully play,while the design length is slightly shorter; Stress of micro-steel pipe piles is smaller,and its effect of controlling deformation is limited,thus its advance supporting effect is poor. The experience gained from this project can be reference for the similar projects in Chengdu. The monitoring data observed are helpful to the study of composite soil nailing wall theory.
出处
《地下空间与工程学报》
CSCD
北大核心
2016年第6期1645-1652,共8页
Chinese Journal of Underground Space and Engineering
关键词
深基坑
土钉墙
微型钢管桩
监测分析
信息化施工
deep excavation
soil nailing wall
micro-steel pipe piles
monitoring analysis
inform ation construction
