深厚冲积层中冻结井外壁钢筋应力的实测研究

介绍龙固副井冻结井外壁钢筋应力的测试方案，分析温度及约束作用对钢筋计测值的影响和不同方向配筋的应力测值变化规律．结果表明：受水化热高温的影响，外壁钢筋首先经历压应力急剧增长阶段，而后竖向及径向钢筋压应力随着井壁降温而逐渐减小，最终处于拉应力或低水平的压应力状态，而环向钢筋则始终处于压应力状态；环向钢筋的应力主要受冻结压力控制，而竖向及径向钢筋的应力主要受温度影响；鉴于深厚冲积层冻结压力增长迅速，外壁竖向钢筋可按承担3d内施工的井壁段自重，取15m高度的井壁段进行设计，从而有效地减少竖向钢筋的配筋率；而环向钢筋应尽号靠近鼻壁内侧配置，以提高井壁的水平承载力。

In-Situ Measurement on the Stress of Reinforcing Steel Bar of Outer Freezing Shaft Wall in Deep Alluvium

The stress-measuring scheme of reinforcing steel bars in the outer freezing wall of Longgu mine auxiliary shaft was introduced, the influences of temperature and constraints on the measuring data of the vibrating wire gages and the variation of stress with the directions of reinforcing steel bars were analyzed. The results show that under the influence of high temperature, all reinforcing steel bars in the outer shaft wall firstly bear sharply increasing compressive stress, then the compressive stress of vertical and radius-directional steel bars gradually decreased with the decreasing of the temperature, some even converted to tensile stress. The tangent-directional steel bars kept compressive stress. The stresses of the tangent-directional steel bars were mainly controlled by the freezing pressure, while those of the others were induced mainly by temperature. Since the freezing pressure increased rapidly in deep alluvium, the vertical reinforcing steel bars should be designed according to the accumulative height of the outer shaft wall segments constructed within 3 days; its upper limit may be assumed to be 15 m. So the amount of vertical ones can be properly reduced. The tangent-directional steel bars should be arranged mainly near the inside surface of the shaft wall, so as to increase the horizontal bear capability of the shaft wall.