基于泥水盾构废浆的新型同步注浆浆液性能及影响因素初探

Preliminary Study on the Performance and Influencing Factors of a New Synchronous Grouting Slurry Based on Slurry Waste from Slurry Shields

为响应我国生态文明建设要求,遵从绿色发展理念以及推进“双碳”战略目标的实现,针对泥水平衡盾构施工过程中产生的废弃浆液的处理及外运的高成本、易污染环境等问题,提出将废弃泥浆用作制备同步注浆浆液的解决办法。依托成都环线紫瑞隧道建设项目,通过室内试验方法研究浆灰比、灰砂比、粉灰比对基于砂卵石土地层泥水盾构废浆制备的新型同步注浆浆液的泌水率、流动度、凝结时间以及3,7,28 d抗压强度的影响规律,得出以下研究结论。(1)基于砂卵石土地层废浆制备的新型同步注浆浆液稳定性良好。(2)新型同步注浆浆液的凝结时间随着浆灰比、灰砂比的增加而增长,随着粉灰比的增加而减小;流动度随着浆灰比、灰砂比的增加而增加,随着粉灰比的增加而减小。(3)新型同步注浆浆液的3,7,28 d抗压强度随着浆灰比的增加而减小,随着粉灰比的增加而增加,随灰砂比的增大呈先增大后减小的变化规律,在灰砂比为0.8时,达到最大值。(4)经试验研究得出使用废浆以浆灰比2.5、灰砂比1.25、粉灰比0.75制备的新型同步注浆浆液3 h泌水率为0,凝结时间为7.25 h,流动度为23.3 cm,3,7,28 d抗压强度分别为1.2,1.5,2.7 MPa,各项性能均满足试验指标要求,将此配比方案应用于依托工程实际施工,能够满足施工现场的要求。此研究为泥水平衡盾构废弃泥浆再利用于同步注浆提供了有效支撑。

In response to China’s requirements for ecological civilization construction,adhering to the concept of green development and advancing the achievement of the"dual carbon"strategy,this study proposes a solution of utilizing the waste slurry for the preparation of synchronous grouting slurry,aiming to address the high cost and environmental pollution of the disposal and transportation of waste slurry produced during the slurry balance shield construction.Based on the construction of Zirui Tunnel of Chengdu Ring Line,laboratory experiments were conducted to investigate the influence of the slurry-cement ratio,cement-sand ratio,and powder-cement ratio on the bleeding rate,fluidity,setting time and compressive strength at 3,7 and 28 d of the new synchronous grouting slurry prepared from the waste slurry of slurry shield in the sand pebble soil layer.The results showed that:1)The new synchronous grouting slurry prepared from the waste slurry exhibited good stability.2)The setting time of the new synchronous grouting slurry increased with the increase of the slurry-cement ratio and the cement-sand ratio,but decreased with the increase of the powder-cement ratio.Fluidity increased with the increase of the slurry-cement ratio and the cement-sand ratio,but decreased with the increase of powder-cement ratio.3)The compressive strength at 3,7 and 28 d of the new synchronous grouting slurry decreased with the increase of the slurry-cement ratio,increased with the increase of the powder-cement ratio,and increased initially and then decreased with the increase of the cement-sand ratio,reaching its maximum value at a cement-sand ratio of 0.8.4)The experimental results showed that the new synchronous grouting slurry prepared using the waste slurry with a slurry-cement ratio of 2.5,a cement-sand ratio of 1.25,and a powder-cement ratio of 0.75 had a bleeding rate of 0 at 3h,a setting time of 7.25 h,a fluidity of 23.3 cm,and compressive strengths of 1.2 MPa,1.5 MPa,2.7 MPa at 3,7,and 28 d,respectively.All the performance indicators met the experimental requirements and the application of this ratio in actual project met on-site construction demands.This study provides effective support for the reuse of waste slurry from slurry balance shield in synchronous grouting.