磁西副立井超千米单层井壁受力变形实测与分析

Field monitoring & analysis on the stressing deformation of single layer lining of auxiliary shaft over 1000 m deep in Cixi Colliery

分析了我国矿山井筒井壁实测的现状和发展。采用振弦式混凝土应变计和钢筋计、有线远程传输、可存储数字采集仪,实施了井壁受力变形传感器埋设和监测,测试深度达到了垂深1 208 m。根据实测数据,对井壁混凝土应变分别进行了内缘与外缘、竖向与环向的对比,钢筋受力应变和混凝土应变之间的对比分析,并通过包神公式进行理论值和实测值的对比分析。对比研究说明了实测结果的正确性、合理性。结果表明,短掘短期单层井壁的内缘环向应力大于竖向和径向应力,符合包神井壁设计公式推导的理论基础,井壁实测期间全过程中出现最大观测值的时间是混凝土井壁砌筑后5~6个月,最大环向应变约为-1 093×10-6,总体平均内缘环向应变为-682×10-6。井壁混凝土环向应变的不均匀系数为2.15,钢筋受力的不均匀系数为1.36。实测结果表明,C60等级,900 mm厚的钢筋混凝土井壁是安全的,可为千米竖井井壁设计提供参考。

The paper reviewed the situation and development of the deformation monitoring of shaft lining. The monitoring system of shaft lining were successfully built with strain and stress sensors of vibrating string type for reinforcement concrete,assisted with remote and digital storable wire transfer instruments,which set up a record in China of shaft lining test with 1 208 m in depth in auxiliary shaft in Cixi Colliery,Heibei Province. Based on the data taken in situ,the concrete strain were comparatively studied from inner to outer,from vertical to hoop,and so do with strain between rebar and concrete. The analytic theory were contrasted with practice according to the 'Baoshen'formula. The results show that the testing results of field measurement is reliable and reasonable,the inner hoop stress is much large than the vertical and radical stress of shaft lining built with the process of alternate enervating and concrete placing with short section,which is very corresponding to the theoretical basis of 'Baoshen'formula derivation of the thickness design of shaft lining. The maximum stress of lining is reported in the 5-6 months after the reinforcement concrete lining had been completed,with the maximum hoop strain of 1 093 × 10-6,and the average inner hoop strain is 682 × 10-6.The uniformity coefficient of the inner hoop strain of concrete lining is 2. 15,while the uniformity coefficient of inner hoop rebar stress is 1. 36. The testing results in situ proves that the lining thickness of 900 mm with grade of C60 con-crete for the shaft lining of depth over 1 000 m is safe and reliable,which can well be referenced to other cases of shaft lining.