New inert grout and combined grouting technology for shield tunneling in upper soft and lower hard water-rich strata

Abstract

The invention provides shield novel inert slurry used for an upper-soft and lower-hard water-rich stratum and a combination grouting technology. The combination grouting technology comprises the stepsthat firstly synchronous grouting novel inert slurry is prepared, then conveyed to a shield backup trolley through a slurry transportation vehicle and pumped to a trolley slurry storage tank, and finally injected into the shield tail through a synchronous grouting pump, and synchronous grouting is completed; and in the shield construction process, the water content of muck is observed simultaneously, through change of the muck water content and a formation analysis result, when it is discovered that the source of water in a soil warehouse is incoming water in the rear of a tunnel, shield driving is stopped, according to the point position corresponding to a rock-soil interface, grouting holes, closest to the rock-soil interface, in two rings of continuous shield segments, meeting the grouting conditions, in the fifth to eighth rings in the rear of the shield tail are selected to serve as secondary grouting holes, and secondary fixed-point grouting is conducted by adopting binary slurry. According to the shield novel inert slurry used for the upper-soft and lower-hard water-rich stratum and the combination grouting technology, the construction cost is low, the effect is good, the phenomenon of water leakage of a tunnel structure can be basically eradicated, the phenomena of segment upward floating or faulting of slab ends are few, and the later-period leaking stoppage and repairing cost of the tunnel is greatly reduced.

Description

Technical field [0001] The invention relates to the technical field of tunnel shields, in particular to a new type of inert grout and combined grouting technology for shields used in upper soft and lower hard water-rich formations. Background technique [0002] Shield synchronous grouting technology means that in the process of shield construction, after the tunnel lining segments are assembled, the tunnel is pulled out of the shield tail at the same time, under a certain grouting pressure, a certain amount of early strength and final strength The grouting material is filled into the gap behind the shield tail, and after it is consolidated and hardened, it can fill the gap in the building behind the wall, provide a certain bearing capacity, and stabilize the lining of the segment. The types of shield tail grouting are divided into post grouting, synchronous grouting, timely grouting and secondary grouting. In the case of stricter requirements for ground settlement control and tun...

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Problems solved by technology

[0004] In addition, when the existing secondary grouting is used as a water-stop ring, the double-liquid grouting of the entire cross-section is carried out, that is, all the grouting holes in the continuous number of rings on the entire circle are grouted to form a water-stop ring. Ring, the grouting method is not targeted, the grouting time is too long, resulting in too long downtime, too much water seepage in front of the face, affecting the stability of the face

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