基于数值模拟分析的基坑变形特征研究
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摘要
为了研究复杂地质条件下深基坑开挖过程中的变形问题,以某基坑工程为例,根据盆式开挖结合两道斜支撑的设计方案,进行了MIDAS/GTS数值模拟,并根据模拟结果进行监测点布设,在基坑开挖过程对变形异常处进行跟踪观测,并进行对比分析。研究结果表明:第一道斜撑施工后,水平及竖直位移最大处均出现在基坑底部,且水平位移较大;第二道斜撑施工后,水平及竖直位移开始增大但仍在预警值范围内;开挖至基坑底部后,预测和实际监测水平及竖直位移均趋于稳定,实际监测结果反映了数值模拟分析的科学性,研究成果可为此类深基坑的开挖提供指导经验。
Numerical analyses using MIDAS GTS for a sloped deep excavation using two layers of inclined supporting(rakers) system were performed to evaluate the deformation characteristics of a deep excavation under complexed subsurface soil conditions in Xuzhou. The construction monitoring locations were optimized based on the numerical analysis results and monitoring data were compared with the analytical results. The results indicate that, after applying the first layer of rakers, both vertical and horizontal deformations were observed at the bottom of the excavation and larger horizontal deformation was monitored. After the installation of the second layer of rakers, both vertical and horizontal deformation increased, and they were within the tolerable zone. When the excavation reached at the final proposed depth, the predicted and monitored horizontal deflections stabilized.
Numerical analyses using MIDAS GTS for a sloped deep excavation using two layers of inclined supporting(rakers) system were performed to evaluate the deformation characteristics of a deep excavation under complexed subsurface soil conditions in Xuzhou. The construction monitoring locations were optimized based on the numerical analysis results and monitoring data were compared with the analytical results. The results indicate that, after applying the first layer of rakers, both vertical and horizontal deformations were observed at the bottom of the excavation and larger horizontal deformation was monitored. After the installation of the second layer of rakers, both vertical and horizontal deformation increased, and they were within the tolerable zone. When the excavation reached at the final proposed depth, the predicted and monitored horizontal deflections stabilized.
引文
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