Construction method of anti-floating anchor rod for karst cave in limestone area

Abstract

The invention discloses a construction method of an anti-floating anchor rod for a karst cave in a limestone area. According to the construction method, a composite film bag is combined with a fractional grouting technology, a large-size inclusion is formed by grouting in the composite film bag in a karst cave and a fracture development section, an anchoring body larger than the hole diameter of an anchor rod is formed in the karst cave, the embolism effect is achieved, meanwhile, a karst cavity is blocked to a certain degree, and the water stopping effect is achieved; and then grouting is conducted on the anchor rod holes in the upper portion and the lower portion of the film bag correspondingly. The anchoring plug plays an effective anchoring role, and then the grouting effect of the upper section and the lower section of the karst cave is effectively guaranteed, so that the anchoring force of the anchor rod can be guaranteed, and the problem that the anchor rod construction in the karst cave and the corrosion crack area is difficult is solved.

Description

technical field [0001] The invention relates to the construction field of anti-floating bolts in karst caves, in particular to a construction method for anti-floating bolts in karst caves in limestone areas. Background technique [0002] The anti-floating anchor rod is a kind of anti-floating measure for the underground structure of construction engineering. It is used to resist the influence of the buoyancy of groundwater on the building structure during underground construction. It is widely used in geotechnical engineering. The specific construction process of the existing anti-floating anchor rod is to drill a hole in the foundation by a drilling rig, insert the completed anti-floating anchor rod into the borehole, and then grout through the grouting pipe in the borehole. [0003] With the development of engineering construction, the depth of the basement is continuously increasing, and many anti-floating anchors are used for the anti-floating of the basement. However, ...

AI Technical Summary

Problems solved by technology

At present, due to the pressure bearing property of karst groundwater, water gushing in the bolt hole is often caused, and the grouting slurry is carried away with the water flow, which affects the quality of grouting. , the grouting effect cannot be guaranteed, often resulting in insufficient engineering anchoring force

Most of the existing anchor bolt construction technologies adopt the measures of artificial precipitation. After the karst groundwater is pumped and its water level is lowered, the cave is backfilled with gravel and sand, etc., and then grouted in stages to ensure the anchorage quality of the anchor bolt; Main problems: 1) During the dewatering and drainage process of karst groundwater, it is very easy to induce geological disasters of karst ground subsidence, which is very harmful; 2) The amount of grouting cannot be large, the construction is complicated, and the progress is slow

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