基于压差传感技术的坑底隆起监测方法及应用
Monitoring method of bottom heave based on pressure difference sensing technique and its application
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摘要: 针对基坑坑底隆起监测问题，提出了一种基于压差传感技术的坑底隆起监测方法。首先分析了压差传感技术原理，其次介绍了监测系统中的压差传感系统及相应的辅助系统，然后通过模型试验验证了监测系统的温度稳定性，最后将该监测系统应用于工程实践，并对监测结果进行了分析。所得主要结论如下：基于压差传感技术的坑底隆起监测系统通过测点处的液面变化来反映竖向位移。基坑坑底隆起值随着开挖深度的增加而增大；开挖深度较小时，坑底隆起随基坑开挖同时发生和结束；当基坑开挖深度不断增加，坑底隆起随基坑开挖同时发生，并在该层开挖结束后持续增大。开挖相同厚度的土层，深度越深，所引起的坑底隆起越大，坑底土体重新稳定所需要的时间也越长。Abstract: A monitoring method of bottom heave based on pressure difference sensing technique was proposed for the monitoring of foundation pit. Firstly, the principle of pressure difference sensing technique was analyzed. Secondly, the pressure difference sensing system and corresponding auxiliary system were introduced. Thirdly, the temperature stability of the monitoring system was verified by the model test. Finally, the monitoring system was applied to the engineering practice, and the monitoring results were analyzed. The results show that the bottom heave increases with increasing of the excavation depth. When the excavation depth is small, bottom heave starts with the beginning of excavation, and ends with the end of excavation. When the excavation depth is large, bottom heave starts with the beginning of excavation, but continued to increases at the end of excavation. When excavating the same thickness of soil layer, the deeper the soil, the greater the heave, and the longer the time of bottom soil stable.
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