弱围岩下盾构隧道单液浆试验及适用性研究

从地下水资源和地表植被保护、隧道结构耐久性的角度出发，单液浆更符合生态环境保护理念。为克服浆液前期强度无法估算、硬化时间不可控，容易堵塞注浆管路等缺点，以能适用低塑性黏土和级配不良砂土地层的单液浆为研究对象，进行水平塌落度、侧限排水固结、泌水性、硬化时间及无侧限抗压强度等试验。研究结果表明：浆液与注浆管路之间的摩擦力、浆液自身的黏滞阻力等引起的注浆压力损失实测值为 0.016 MPa，相对于注浆压力可忽略不计；单液浆性能发展时间的准确把握是可以完美契合盾构高效掘进对时间的要求；浆液的强度随着固结压力的增加而增加；基于试验数据的地表沉降预测值和监测值的相互比较，验证了将固结排水试验中浆液在一定压力下可承受部分强度的理论引申到盾构施工过程中具有合理性。

Laboratory Testing and Applicability Study on Mono-Mortar for a TBM Tunnel under Soft Ground Condition

In terms of groundwater protection, surface vegetation protection, and tunnel structure durability, mono-mortar caters the demand of ecological environment protection more. Based on this, this study conducted tests of the horizontal slump, oedometer, bleeding, setting time, unconfined compressive, etc. on mono-mortar, which is applicable to lean clay and mixed-grained soils. This study aims to investigate the physical and mechanical properties of mono-mortar, providing solutions for problems such as in estimating early strength, the uncontrollability of hardening time, and the easy blockage of grouting pipeline. The results show that the measured grouting pressure loss caused by friction and viscous resistance between the mortar and pipeline is 0.016 MPa, which is negligible compared with the grouting pressure; the performance development of mono-mortar efficiently satisfies the tight schedule for TBM (Tunnel Boring Machine) heading; the bearing capacity of mono-mortar increases with the oedometer pressure; comparing the predicted and recorded ground settlement values verifies the reasonability of the oedometer test theory in that the mortar can bear strength under a certain pressure in the annular gapgrouting process.