大宁水库防渗墙受回填施工影响的现场监测

选择大宁水库防渗墙受回填施工影响较大的10榀墙体和3个剖面设置监测仪器，对防渗墙随填土施工过程墙体中的混凝土应变、钢筋骨架内力、上墙两侧土压力、下墙顶面土压力及墙体偏斜情况等进行了实时动态自动连续监测，而墙体沉降则采用人工间断性实测。监测结果表明，填土施工引起的墙体应力、应变和内力呈现出下墙大于上墙，而水平位移和沉降则是上墙大于下墙。同时，回填土进度快慢对墙体的作用效果也不同；墙体的应力、应变等在填土完成后逐渐趋于稳定。

Field monitoring of backfilling impact on cut-off wall for Daning Reservoir

The 10-frames wall and three sections of the cut-off wall for Daning Reservoir significantly impacted by its backfilling are selected for installing the monitoring devices，so as to carry out the real-time dynamic and continuous monitoring on the concrete strain，internal force of steel reinforcing framework，lateral soil pressures on both the sides of the upper-wall，soil pressure on the crest of the lower-wall，inclination of the wall，etc. during the backfilling of the wall. However，the discontinuous manual measurement is adopted for the settlement of the wall. The monitoring result shows that the stress，strain and internal force of the wall are larger in the lower-wall than those for the upper one，while the horizontal displacement and settlement of the upper-wall are larger than those of the lower one. Simultaneously，the wall is also impacted by the construction progress of the backfilling，and then the stress，strain，etc. of the wall are to be gradually stabilized after the completion of the backfilling.