土钉和桩锚组合式支护体系受力和变形的数值模拟

Numerical Simulation of Stress and Deformation on Combined Retaining System of Soil Nails and Pile-anchors

摘要:

针对深基坑的土钉和桩锚组合式支护体系，通过数值计算分析基坑开挖过程对支护体系结构的位移、应力及稳定安全系数等的影响，分析基坑开挖过程引起的地层变形规律。对2种基坑支护方案进行计算，其一为采用2道土钉加上1道锚杆的土钉与桩锚组合式结构，其二为采用4道土钉加上3道锚杆的土钉与桩锚组合式结构。根据计算结果，对不同支护方案下基坑的支护效果进行了对比研究，进而分析支护方案的可行性，最后将现场实际采用的支护方案与实测结果进行了比较。

关键词:基坑支护;土钉;桩锚;支护体系;数值模拟

Abstract:

To the combined support system of soil nailing and pile-anchor for deep excavation, by the numerical calculation with FLAC3D software, the analysis is made on the influence of excavating process to displacement, stress and stability safety factor of support system structures, as well as the laws of ground deformation caused by excavation. 2 retaining schemes are considered; one is the retaining structure composted by 2 layer soil nails and 1 pile-anchor, the other one is the retaining structure composted by 4 layer soil nails and 3 pile-anchors. Based on the calculation results, comparative study is carried out on the support effects of different schemes to analyze the feasibility of the support scheme. The paper presents the comparison of support effects between the adopted scheme in the engineering and field measured results.

Key words:foundation pit support; soil nail; pile-anchor; support system; numerical simulation