Precautions for grouting in tunnel construction
The grouting material directly affects the effect of water blocking, seepage prevention and consolidation to a large extent, and is related to the grouting process, construction period and engineering cost.
A large number of engineering practices have proved that if there is a large amount of water gushing or the water pressure is large during construction, the comprehensive permeability coefficient of the tunnel surrounding rock is greater than 10-6 ~ 10-5 cm/s, it is necessary to adopt grouting water stop measures to reduce the tunnel water gushing.
At present, cement and cement chemical slurries (mainly cement-water glass) are the most widely used. The water glass has a fast setting speed and good water stopping effect, but the strength is not high. For some microcracks, fine cement with good water shutoff rate can be considered, but it is expensive, and its cost is usually 3 to 4 times that of ordinary Portland cement. Regarding chemical slurries, especially polymer chemical slurries, in addition to the high cost, the harmful effects of chemical slurries on the environment should also be considered, so its use is restricted. For example, in Norway and Sweden, public health officials prohibit the use of chemical grouting materials due to potential public health risks.
Tunnel mud purification machine
Mud Cleaning System is widely used in the purification and recycling of mud for the construction hydropower, continuous concrete wall, slurry shield tunnel, etc. The mud cleaning equipment is increasingly becoming a necessity of civilized construction since it not only can cut down construction cost, but also can reduce the pollution of the environment.