Grouting Technology In Shallow Buried Tunnel With Fractured Belt

Fractured belt of fault are the common poor geologic body during constructing tunnels, it is very unfavorable to the stability of the surrounding rock of the tunnel and become one of the key factor which control the construction of the tunnels, especially to the tunnels which were shallow buried. As for mass of practice on the mountain range's tunnel, grouting technology has already become very mature. But for the tunnel with fractured belt of fault, it is still a new challenge. The constructing shallow burred YINPANLU tunnel, which cross the XIANGJIANG River, will meet several faults which with are 140m,8m and 100m individually, which is unusual for the common tunnel. According to the detailed in-situ geological investigation, physic-mechanical test and grouting material test, together with the three dimensional numerical technology, several results with grouting technology aimed at the fractured belts were obtained as follows:(1) Detailed investigated the shallow berried tunnel and the tunnel which met the fractured belt of fault, recognized that the fractured belt are one of the main factors which control the procedure or construction, and the grouting technology is the principal procedure.(2) In-situ geological investigation and test indicate that the fractured belt is a kind of weak rock mass with low strength, deformable and high hydraulic permeability, which were unfavorable to the surrounding rock mass.(3) The grouting mechanics of the fractured belt were analyzed carefully, the results indicate that the grouting material is belonging to a Bingham fluid, and the grouting mechanics is pressing grouting and split grouting.(4) A serial grouting material indoor test of superfine cement-soluble silicate was carried out, and the right mixture ratio was obtained;(5) Based on the three dimensional numerical method, the grouting effect and the response with several grouting thickness of the surrounding rock mass of the tunnel were studied, and a serial results were obtained, which can be used in guide the grouting constructing of the tunnel while cross the fractured belts.