Causes of ground subsidence and uplift during construction of trenchless drilling rigs

In the construction of trenchless drilling rigs, the improper arrangement of the sealing ring of the pipe joint or the damage of the pipe end due to uneven force will lead to the loss of water, and then cause ground settlement and arching. If the thixotropic mud friction reduction technology is used for pipe jacking construction, the leakage of the pipe joint will also constitute the loss of thixotropic mud, causing ground settlement and arching. When the trenchless drilling rig performs deviation correction or curve jacking, it often forms an open space, and the surrounding soil fills the open space, which simply leads to ground subsidence. If the thixotropic mud friction reduction technology is used for pipe jacking construction, the ground settlement will be easily caused if the grouting is not timely.

During the construction of trenchless drilling rigs, it is caused by the influence of factors such as changes in soil quality and the inability to correctly grasp the soil pressure. In other trenchless applications, the cutting area of the cutter head of the pipe jacking machine is too small and the adjustment of the propulsion speed is not appropriate, which also easily causes the earth pressure unbalanced arch, ground settlement and arching. In the construction of trenchless drilling rigs, the pipeline will collide with the surrounding soil when it is pushed forward. When the shape of the pipe joint is uneven, the interface is uneven or the pipeline is not straight, the disturbance of the conflict will be aggravated. rise.

Ground subsidence and arching may occur during or after the construction of trenchless drilling rigs. The above-ground changes on both sides of the pipeline axis will easily affect the surrounding construction and road traffic, and even endanger safety. In pipe jacking construction, there may be various reasons for ground settlement and arching, which need to be analyzed one by one and treated differently.

The trenchless drilling rig has summarized many methods in tunnel excavation and excavation through many scientists and working technicians. Drilling by hand, hammering and drilling holes, detonating individual charge packs one by one with fire detonators, developing to drilling with rock drilling rigs or dobby drilling rigs, using millisecond explosion, pre-split explosion and smooth explosion and other explosive skills. According to the quality conditions, section size, support methods, construction period requirements, construction equipment, skills and other conditions, the tunneling method is selected. However, this method will cause great damage to the surrounding buildings, and will generate a lot of dust, which is exactly the place where the cultural relics cannot be destroyed, so the explosion method must not be used.