城市轨道交通盾构同步注浆国内外现状及发展

同步注浆工艺作为盾构施工中的重要环节,其注浆效果对盾构掘进中的沉降控制与及时包裹管片起到重要作用。针对壁后同步注浆的作用进行分析,系统总结同步注浆浆液类型与要求,对比分析3种常用浆液优缺点,结合工程实际需求探讨浆液需求及发展方向。统计国内已建35个地铁盾构施工案例,分析地铁施工采用盾构机类型及管片尺寸,简要分析盾构隧道同步注浆中的热点问题并展开讨论。研究结果表明:浆液种类需根据地层条件进行选取,国内盾构隧道施工过程同步注浆采用单液浆(惰性浆液、可硬性浆液)较多,盾构隧道施工同步注浆双液浆开始逐渐推广,国外盾构隧道施工同步注浆已逐渐向双液浆转变;壁后注浆准确探测与评价对于注浆效果的反馈与地层变形敏感地区至关重要,相关研究有待进一步加强;在含水量大于30%的地层、渗透性极高地层、软弱不均地层且周围近距离穿越建(构)筑物,对沉降控制要求较高的工程中,建议采用双液浆同步注浆施工或辅以克泥效特殊浆液进行施工。

Present Status and Development of Simultaneous Grouting of Shield Tunnel in the Urban Rail Transit Industry

As an important part of shield construction, synchronous grouting technology plays a significant role in settlement control and timely encapsulation of segments in shield tunneling. Based on analysis of the function of synchronous grouting behind the segment, the types and requirements of synchronous grouting slurry are systematically summarized and the advantages and disadvantages of three common types of grout are compared and analyzed. The slurry requirements and development directions are discussed according to the specific engineering requirements. Thirty-five shield tunneling cases have been counted in China. The types of shield tunneling machines and segment sizes used in metro construction are analyzed. The hot issues in synchronous grouting of shield tunnels are briefly analyzed and discussed. The results show that: The type of slurry is selected according to the stratum properties. The domestic shield tunnel construction process of synchronous grouting increasingly adopts single liquid slurry (inert slurry, hard slurry) and double liquid pulp has begun to develop and popularize. Synchronous grouting of shield tunnel construction abroad has gradually changed, doubling the quantity of liquid slurry. Accurate detection and evaluation of back-wall grouting is very important for feedback on grouting effects and sensitive areas of formation deformation and requires further corresponding research. In strata with water content greater than 30 %, the permeable high strata, weak and uneven strata, and surrounding close range are constructed; in projects with high settlement control requirements, double liquid slurry synchronous grouting is suggested for use in construction, potentially supplemented by special slurry with clay effects.