盾构渣土原地资源化利用研究

Research on theon-situ resource utilization of shield tunneling spoil

城市盾构工程渣土就地处理已成为亟待解决的工程难题。以杭州之江路输水管廊及道路提升工程为背景,取现场废砂、废浆进行再利用为石灰基盾构同步注浆浆液配比试验。通过与现场原配比浆液稠度和泌水率对比,分析了盾构渣土再利用为石灰基盾构同步浆液的可行性及配比方案。研究发现:1)盾构泥水处理系统应对盾构渣土进行分级,将渣土分级为泥浆、细砂、石块,便于后续再利用。2)泥水盾构渣土中的废弃细砂、废浆均可再利用为石灰基盾构同步注浆材料。废砂的使用配比,应综合考虑废砂与工程用砂粒径分布、初始含水率的差异。废浆的使用,应综合考虑其相对比重与其所含膨润土的含量。3)通过减少减水剂添加量,可显著增加盾构废砂、废浆分级再利用配制出的石灰基同步注浆浆液的稠度,使其满足工程需要。研究结果表明:盾构废砂、废浆经分级后可以再利用配制石灰基同步注浆浆液,为盾构废砂、废浆处理提供一定的参考。

The on-site treatment of spoil produced from urban shield tunneling construction has become an urgent engineering challenge to us.By taking the water supply pipeline and road improvement project of Zhijiang road,Hangzhou as a background,this study explores the reuse of on-site waste sand and waste slurry for the mix design of lime-based shield simultaneous grouting slurry.By comparing the viscosity and bleeding rate of the field original mix,the feasibility and mix design of reusing shield tunneling spoil for lime-based shield simultaneous grouting slurry are analyzed.It is found that the shield tunneling slurry treatment system should classify the spoil into mud,fine sand,and stones,facilitating subsequent reuse.The waste fine sand and waste slurry from the slurry shield tunneling spoil can both be reused as lime-based shield simultaneous grouting materials.The mix proportion of waste sand should consider the differences in particle size distribution and initial moisture content between waste sand and engineering sand.The use of waste slurry should take into account its relative density and the content of bentonite it contains.By reducing the amount of water reducer added,the viscosity of the lime-based shield backfill simultaneous grouting slurry prepared from the classified waste sand and waste slurry can be significantly increased,meeting the engineering requirements.The study results indicate that shield tunneling waste sand and waste slurry can be reused to prepare lime-based shield backfill simultaneous grouting slurry after classification,providing a reference for the treatment of shield tunneling waste sand and waste slurry.