泥水盾构浅埋段侧穿房屋沉降控制措施及沉降机理

Settlement control and analysis as slurry shield side crossing building

以广州地铁某盾构区间为工程背景,研究分析浅埋段盾构侧穿房屋时的控制措施及沉降机理。主要结论如下:(1)在盾构通过前,预先对房屋地基进行处理,进行地基土改良,能较好地起到隔水及增强土体稳定性的作用;(2)在施工过程中做好各类数据采集,如出渣量、实时沉降等,经处理分析能较真实地反映目前施工状态,并可及时进行相应的措施调整;(3)在盾构掘进过程中,维持各项参数的稳定性及匹配,是安全快速掘进的基础;(4)由于设备自身原因及地质条件的复杂性,盾构掘进会不可避免地造成土体变形沉降;(5)采用同步注浆及壁后注浆相结合的方式,可有效控制地面及房屋的沉降范围;(6)由于盾构环形空间的存在、浆液凝固时间的时效性,地面沉降主要产生在盾构通过时及通过后;(7)由于房屋基础的整体性限制,房屋沉降主要为盾构通过后的后续累积沉降;(8)沉降的分布方式符合Peck理论的预测。

Based on the engineering background of a shield tunnel in Guangzhou metro,the control measures and settlement mechanism of the side tunnel in the shallow buried section are studied and analyzed. The main conclusions are as follows：（ 1） in front of the shield tunnel,the foundation soil can be improved,which can effectively play the role of water isolation and enhance the stability of soil;（ 2） all kinds of data are to be collected in the construction process,such as the amount of slag,real-time settlement,the analysis can be more realistic to reflect the current state of construction,and timely manner to adjust the corresponding measures;（ 3） in the shield tunneling process,maintain the stability of the parameters and matching is the basis of rapid excavation;（ 4） because of the complexity of equipment for their own reasons and geological conditions,the shield will inevitably cause the settlement and deformation of soil;（ 5） using synchronous grouting and grouting combination,can settlement effective control of land and housing;（ 6） due to the timeliness of the shield of the annular space exists,slurry solidification time,ground subsidence is mainly produced in the shield pass-ing through and after;（ 7） the overall limit of building foundation,the housing settlement mainly for the subsequent accumulation after the shield through the settlement;（ 8） the distribution of the settlement with the predictions of Peck theory.