某深基坑施工中土体位移的监测分析

Monitoring and Analysis of Soil Displacement in Construction of Deep Foundation Pit

通过对西安某深基坑桩锚联合支护结构的桩后土体位移的监测,分析了基坑不同部位桩后土体沿垂直坑壁方向位移的变化规律。监测分析结果表明:基坑的开挖使地应力重新分布,引起桩后土体水平位移逐渐增大;整个基坑开挖过程中,土体沿垂直坑壁方向的位移呈现较明显的抛物线形阶梯状变化,位移速率波浪线形变化;基坑内降水会引起周围土体往基坑方向位移,不合理降水既使桩后土体位移增加,还会对周围建筑物造成影响。将监测信息反馈给施工单位,及时调整施工方案,做到信息化施工,确保基坑和周围建筑物的安全稳定。分析结果对于类似基坑工程具有参考作用。

Through monitoring the soil displacement behind piles in pile-anchor support structure for a deep foundation pit in Xi＇an, the change law of such displacement along the vertical direction of pit wall at the different positions in this pit was analyzed. The results of monitoring and analysis show that the excavation of foundation pit makes geostress redistribute, then the horizontal displacement of soil behind piles increased gradually; in the whole process of excavation, the soil＇s displacement along the vertical direction of pit wall changes like parabolic curve in steps, and the displacement rate like wavy line; the dewatering therein may cause the surrounding soil to move towards the pit, and the irrationalities thereof give not only increment on the soil displacement, but also impact on the structures around. Feeding back the monitoring information to the builders, adjusting the construction plan in time and implementing informationized construction are the key to ensure the safety and stability of the foundation pit and surrounding structures. The analysis result may have the reference value in similar projects.