复合地层盾构下穿建筑物渣土改良与滚刀寿命预测研究

发布时间：2018-04-13 06:49

本文选题：土压平衡盾构 + 复合地层　；参考：《西南科技大学》2017年硕士论文

【摘要】：随着城市的高速发展,我国各大中城市地铁建设进入高峰期,盾构法因其高效、安全性高、对周围环境影响小等特点而被广泛的使用。在市区经常会遇到盾构下穿建筑的情况,下穿时降低地面沉降,保证建筑物的安全成为重中之重。渣土改良和换刀地点的选取是保证盾构顺利下穿的关键技术。本文根据深圳地铁7号线福民站~皇岗口岸站盾构区间地质情况,确定改良剂、试验样土和渣土改良试验设计,通过坍落度、渗透和电机搅拌试验,得出不同地质情况的最佳泡沫添加比。将试验结果应用到现场进行验证,通过对比渣土改良前后,渣土温度、盾构停机后土仓压力变化和渣土状态,得出试验结果可靠。将试验结果应用到盾构掘进渣土改良中,并记录正面滚刀的磨损量。根据滚刀的工作原理和磨损机理,建立滚刀寿命预测模型;对比滚刀磨损的实测值和模型预测值,两者相差不大,证明该模型是合理的;通过该模型,得出不同安装半径正面滚刀的最大掘进距离,并找出所有滚刀中最短掘进距离。再根据下穿建筑物段的长度、滚刀最短掘进距离和盾构停机影响范围,确定了最佳换刀地点。盾构下穿时,对地面建筑物沉降、隧道拱顶沉降和水平收敛进行监测,监测结果满足规范要求,盾构顺利掘进,建筑物安全,说明盾构下穿前各项工作准备较充分,渣土改良泡沫添加比和滚刀寿命预测模型准确。本文提出的渣土改良方案和滚刀寿命预测模型,降低了盾构下穿建筑物的风险。研究成果可以很好的与实际盾构施工结合起来,为今后类似工程起到指导作用。
[Abstract]:With the rapid development of cities, subway construction in large and medium-sized cities in China has entered the peak period. The shield method has been widely used because of its high efficiency, high safety and little impact on the surrounding environment.In the urban area, it is often encountered under shield tunneling to reduce the ground subsidence and to ensure the safety of buildings becomes the top priority.The improvement of residual soil and the selection of tool changing location are the key techniques to ensure the smooth penetration of shield tunneling.According to the geological conditions of shield section of Fumin Station ~ Huanggang Port Station on Shenzhen Metro Line 7, the paper determines the improver, test sample soil and residue soil improvement test design, through slump, penetration and motor stirring test,The optimum foam addition ratio for different geological conditions is obtained.The test results were applied to the field to verify. By comparing the residual soil temperature before and after the residual soil improvement, the pressure changes of the silo and the state of the residual soil after the shield machine stopped, the test results were obtained to be reliable.The test results are applied to the residual soil improvement of shield tunneling, and the wear rate of the front hob is recorded.According to the working principle and wear mechanism of hob, the prediction model of hob life is established, the difference between the measured value of hob wear and the predicted value of model is not different, it is proved that the model is reasonable.The maximum driving distance of front hob with different mounting radius is obtained, and the shortest driving distance of all hobs is found out.According to the length of the underpass building section, the shortest driving distance of hob and the influence range of shield machine stop, the optimal tool changing location is determined.The ground building settlement, tunnel dome settlement and horizontal convergence are monitored when the shield is driven under the shield. The monitoring results meet the requirements of the specification, the shield tunneling smoothly, the building safety, which shows that the preparation of the work before the shield tunneling is quite adequate.The modified foaming ratio of residual soil and the prediction model of hob life are accurate.In this paper, the residual soil improvement scheme and hob life prediction model are proposed to reduce the risk of penetration under shield.The research results can be well combined with the actual shield construction, and play a guiding role for similar projects in the future.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.43

【参考文献】