盾构弃渣在岩溶充填注浆材料中的资源化利用

Utilization of Shield Waste Muck in Karst Grouting Material

为经济、环保地处理盾构弃渣,依托南宁国际空港综合交通枢纽城市轨道交通机场线引入机场盾构隧道工程,探讨盾构弃渣就地消纳用于岩溶充填注浆原料的可行性。首先,选用L16(44)的正交试验设计,开展盾构弃渣制备岩溶注浆材料室内试验,并研究各影响因素对于浆液性能指标的影响规律;其次,通过多目标-理想点法获取浆液最优配合比;最后,将研究成果成功应用于工程现场。研究结果表明:1)盾构弃渣用于岩溶充填注浆原料是可行的,一定程度上解决了盾构弃渣的处理问题,且该注浆材料可满足后续盾构安全高效掘进;2)在最优配合比(水灰质量比∶盾构弃渣掺量∶速凝剂掺量∶膨胀剂掺量=1.41∶35.80%∶0.48%∶0.31%)下浆液各性能参数均符合岩溶充填注浆要求;3)注浆后取芯样发现,浆液与岩溶充填物胶结紧密,后续盾构掘进过程无异常突变情况,注浆和掘进效果达到预期,且盾构弃渣在简易处理后即可实现浆液现场快速配制,可节省约30%的材料成本,其经济与环境效益显著,具有广泛的推广及应用价值。

The widespread use of the shield method has raised the challenge of economically and environmentally managing shield waste muck,which is a crucial factor limiting its efficient implementation of the shield method.In this study,a case study is conducted on an airport shield tunnel project at the Nanning International Airport Comprehensive Transportation Hub Urban Rail Transit Airport Line,and the feasibility of employing shield waste muck for in-situ absorption in the production of raw materials for karst grouting is discussed.An L16(44)orthogonal test design is employed to perform indoor tests on karst grouting materials made from shield muck.Herein,the impact of various factors on the slurry′s performance index is examined.The optimal slurry mixing ratio is determined using the multitarget-ideal point method.Finally,the research findings have been successfully put into practice at an engineering site.The results demonstrate the following:(1)Shield waste muck is a viable raw material for karst grouting,partially resolving the issue of shield muck treatment.The resulting grouting material satisfies the safety and efficiency requirements for subsequent shield tunneling.(2)Under the optimal mixing ratio(water-cement ratio,shield waste muck content,quick-setting agent content,and expansion agent content of 1.41,35.80%,0.48%,and 0.31%,respectively),the slurry′s performance parameters comply with the karst filling and grouting standards.(3)Examination of the core sample post grouting reveals a strong bond between the slurry and karst filling,ensuring a smooth subsequent shield tunneling process without any unexpected deviations.The grouting and excavation effects align with expectations,and on-site preparation of shield waste muck after simple treatment results in material cost savings of approximately 30%.The economic and environmental benefits of this approach are noteworthy and merit widespread adoption.