Construction method of concrete cut-off wall in sludge soil with high water content

Abstract

The invention relates to a construction method of a concrete cut-off wall in sludge soil with high water content. The construction method mainly comprises the steps of building a guide wall, preparing high-specific-gravity slurry, carrying out joint drilling to form grooves by an abrasion drill and an impact drill which are combined with each other, cleaning the bottom and replacing slurry, carrying out joint construction, manufacturing and installing a steel reinforcement cage, pouring concrete and the like. A construction technology of the concrete cut-off wall designed by the invention is suitable for carrying out high-quality drilling and grooving on river dams under the condition of a soft soil foundation by virtue of an abrasion drill and a percussion drill which are combined; the construction mechanism is clear and the construction quality is easy to control; after the construction is finished, a strict detection means and a reliable reinforcement measure can ensure that the engineering quality meets the design requirements, and the possible problem of hole collapse of the cut-off wall on the river dam can be thoroughly solved; multiple groups of devices can be easily organized to enter sites for construction, so that the construction period is ensured; and the construction method is easy to popularize in large area and especially applicable to river dam engineering in the sludge soil with the high water content.

Description

technical field [0001] The invention relates to a construction method of a concrete anti-seepage wall, in particular to a construction method of a concrete anti-seepage wall in muddy soil with high water content. Background technique [0002] The concrete cut-off wall is an important civil engineering project installed in river dams to prevent flood soaking and erosion and eliminate hidden dangers of piping. At present, the mature construction methods of concrete cut-off walls widely adopted by various countries mainly include the following: [0003] ①Multi-axis continuous cement deep mixing method: This method usually uses one pump to supply multiple nozzles, so that one or more nozzles are prone to clogging during construction, and it is not easy to find during construction, thus forming a seepage barrier Discontinuous, resulting in concentrated leakage; in addition, affected by the equipment capacity, the depth of the wall is not enough, it is only suitable for homogeneo...

AI Technical Summary

Problems solved by technology

[0003] ①Multi-axis continuous cement deep mixing method: This method usually uses one pump to supply multiple nozzles, so that one or more nozzles are prone to clogging during construction, and it is not easy to find during construction, thus forming a seepage barrier Discontinuous, resulting in concentrated leakage; in addition, affected by the equipment capacity, the depth of the wall is not enough, it is only suitable for homogeneous sand and soil foundation, and the wall is generally too thick, and the construction scope is too large. There are changes, and there is no effective and reliable testing method, so it is difficult to guarantee the construction quality; ②Three vertical pipe rotary spraying, fixed spraying, swinging spraying method: this method requires strict control and guarantee of the verticality and spacing of the three vertical pipes during construction and spray pressure

However, during the construction process, due to the difficulty in controlling the verticality differences of the three vertical pipes, it is easy to cause large deviations in the deep layers of the soil, and cannot form a continuous curtain, resulting in discontinuity and spraying leakage; ③ Claw bucket type thin Diaphragm wall method: Although this method has a clear process and reliable quality assurance, it is difficult to insert rocks, the construction process is complicated, and the construction period is long. Before pouring, the soil (sand) on both sides of the groove may collapse, and the groove will be filled. It affects subsequent pouring, and there is no reliable detection method, so the construction quality cannot be guaranteed, and the project cost is high

④ Wall formation by jetting water: the main disadvantage of this method is that before pouring, the soil (sand) on both sides of the groove may collapse, and the groove will be filled and blocked. It is suitable for the construction of homogeneous sand and soil foundation; ⑤Thin-walled continuous anti-seepage curtain: the technology of thin-walled continuous anti-seepage curtain adopts plate-guided, position-limited, and equal-thickness lap joints. Craftsmanship, so that the curtain is continuous as a whole, and the seams have no construction gaps

Although this method has the advantages of high work efficiency and reliable quality, once the depth of the cut-off wall is required to be more than 30m, the thickness of the sand layer is about 25m, and the lower part of the sand layer still contains a small amount of boulders with a maximum particle size of about 50mm. When it is required to embed 50cm into the weathered bedrock, this rule cannot insert or pull out the plugboard, that is, normal construction cannot be realized

Images