泥水盾构施工废弃泥浆对同步注浆材料性能的影响

泥水盾构施工会产生大量废弃泥浆，传统的抛弃堆放不但污染环境且占用土地资源。依托南京长江新济洲供水廊道项目泥水盾构工程，针对江底盾构施工中的废弃泥浆，开展了将其应用于同步注浆材料的可行性研究。通过室内试验，研究了泥浆固水比、膨润土替代率和废弃泥浆黏粒含量对注浆材料性能的影响，同时对比分析了新配制膨润土泥浆和废弃泥浆对注浆材料性能影响的差异。结果表明：增大泥浆固水比，可使砂浆凝结时间缩短、强度增大、泌水率和体积收缩率降低，但会导致砂浆流动性变差。相比于新配制膨润土泥浆，废弃泥浆制备的砂浆具有更优的流动性能，但存在泌水率偏大和强度偏低的问题。采用废弃泥浆替代部分新配制膨润土泥浆，则能够有效控制砂浆的泌水率增大和强度降低的问题，同时使砂浆的流动性能大幅提高；废弃泥浆黏粒含量对砂浆性能影响相对较小，一定程度上表明了使用不同地层废弃泥浆制备的砂浆性能差异不大，故无须随地层变化而对砂浆配比进行较大调整，便于实际工程施工应用。

Influence of Waste Slurry from Slurry Shield Construction on the Properties of Synchronous Grouting Materials

A large amount of waste slurry will be produced during slurry shield construction, and the traditional treatment method will lead to environmental pollution and land resource occupation. Based on the slurry shield engineering of Xinjizhou water supply corridor project in Nanjing Yangtze River, the feasibility of using waste slurry in shield construction as synchronous grouting material were discussed. The influence of slurry solid water ratio, bentonite substitution rate and waste slurry clay content on the performance of grouting materials were investigated; furthermore, the influence of bentonite slurry and waste slurry on the performance of grouting materials were compared and analyzed. The results show that mortar can obtain shorter setting time, higher strength, smaller bleeding rate, lower volume shrinkage and poor fluidity, with the increase of slurry solid water ratio; compared with newly prepared bentonite slurry, the mortar prepared by waste slurry can obtain better fluidity, but obtaining higher bleeding rate and lower strength at the same time; if the newly prepared bentonite slurry is partially replaced, the bleeding rate and strength of the mortar can be controlled, and the fluidity of the mortar can be greatly improved; the waste slurry clay content has little influence on performance of mortar, to some extent, it indicate that the mortar prepared by waste slurry produced in different stratum has similar properties, therefore, it is unnecessary to signifcantly adjust the proportioning of mortar with the change of construction stratum, which is convenient for engineering construction application.