注浆处治盾构下穿建筑物渗水沉降的效果分析

Grouting Lifting Effect on Building Settlements Induced by Seepage during Shield Tunnelling

天津地铁3号线盾构下穿某既有建筑物时因地下水渗漏引起建筑物沉降,文章以注浆抬升处治工程为研究对象,结合监测数据,采用数值模拟方法分析了在隧道渗水条件下注浆抬升既有建筑物的效果,在此基础上分析了注浆点位置、注浆时间对注浆抬升效果以及对隧道的影响。研究结果表明:浅孔注浆时补偿注浆率较高,所需注浆量明显低于深孔注浆,但补偿注浆率波动程度较大,建筑物倾斜显著增加;深孔注浆时注浆压力导致隧道弯矩急剧增大,为浅孔注浆时的3.7倍,隧道弯矩影响范围均约为注浆区宽度的1.5倍;适当增加单次注浆时间,建筑物倾斜增量较小,且建筑物测点抬升量显著增加,补偿注浆率明显增大,注浆抬升效果更好。

Settlement occurred at an existing building during shield construction of Tianjin Metro Line 3 due to ground water leakage. Based on the measured data, a numerical simulation was adopted to analyze the grouting lifting effect on the existing building under the condition of water leakage, and the effects of location of the grouting points and grouting time on the grouting lifting and tunnel were also analyzed. The research results show that the compensation grouting rate is relatively high and the required grouting voXume for the shallow-hole grouting is obvi- ously much less than that of deep-hole grouting, but the fluctuation of the compensation rate is large and the build- ing inclination increases significantly; the bending moment of the tunnel increases sharply because of the grouting pressure during deep-hole grouting, it is 2.7 times greater than that for shallow grouting, and the influential scope of tunnel bending is around 1.5 times the grouting width; and with proper timing of the grouting, the building inclination increment is relatively small while the lifting of the measuring points and the compensation grouting rate increase significantly, and the effect of grouting lifting is better.