隧道超前注浆对既有建筑物影响现场测试分析

Field Test and Analysis of the Influence on the Existing Building by Advanced Grouting in Tunnel

为研究隧道注浆引起的上部建筑物变形特性及其损坏原因,以深圳某地铁下穿建筑物实际工况为背景,结合注浆施工统计和现场测试数据对建筑物隆起、倾斜及开裂过程进行分析。分析结果表明:现场注浆存在控制终压过大、施工不规范等问题,造成浆液劈裂地层,因此注浆量和注浆速率异常增大,上部建筑物表现为急剧隆起,最大单日隆起量达41.55 mm,注浆结束后建筑物竖向位移逐渐减小最终趋于稳定;注浆期间,建筑物外侧墙体倾斜初始呈现出"前后向内,两侧向外"的趋势,并随注浆施工转变为"前后向外,两侧向内";建筑物裂缝以角部受剪裂缝居多,测试期间未发生明显开展或闭合。最后针对隧道注浆施工提出几点建议,可为类似工程提供借鉴。

To study the deformation characteristics and damage during grouting stage when a subway tunnel passes through underneath a structure,the changing process of uplift,tilt and cracks of the superstructure and failure causes re obtained by means of field investigation. The analysis results are as follows: Problems such as excessive grouting pressure and improper operations exists during grouting,causing the slurry to split the formation. Therefore,the grouting amount and grouting rate increase rapidly,and the vertical displacement of the building increases sharply,with the maximum one-day growth of 41. 55 mm. After grouting,the vertical displacement of the building decreases gradually and finally stabilizes. During the grouting stage,the initial inclination of the building walls shows as the front and rear walls lean inward and the walls on both sides lean outwardand changes with the grouting process to the front and rear walls lean outward,and the walls on both sides lean inward Most of the building cracks are shear cracks in the corner with no obvious opening or closing during the test. Based on the field measurement and analysis,some suggestions have been put forward for the tunnel grouting construction,which can be used as a reference for similar projects.