特厚表土层冻结井筒外壁受力监测与分析

Monitoring and Analysis of Stress Acting on Outer Freezing Shaft Wall in Special Thick Alluvium

对穿过特厚表土层的关键层冻结井筒外壁所受的冻结压力、井壁钢筋应力和混凝土应变进行了实测。获取的数据表明,井筒外壁环向主要受冻结压力,竖向主要受温度拉应力。环向混凝土最大应变-1 517με,环向钢筋最大应力-240 MPa,均小于设计值,外壁一直处于安全状态。

The freezing pressure of the outer wall of the frozen shaft which passes through the key layer of the extra thick surface layer＇ the stress of the reinforced concrete wall and the strain of the concrete are measured. The data obtained indicate that the outer wall of the shaft is mainly affected by the freezing pressure, and the vertical out shaft wall is mainly controlled by the temperature tensile stress. The ring maximum strain of the concrete is the epsilon -1 517 De,the greatest ring reinforced stress is -240 MPa, which are lower than the design value, the outer wall in the security has been in a state.