A construction method for expansive soil subgrade with high groundwater level and low filling and shallow excavation

Abstract

The invention relates to the technical field of rail roadbed structures, in particular to a construction method for a light-filling shallow-excavation expansive soil roadbed with high underground water level. The construction method comprises the following steps of: excavating foundation soil until the bottom surface of a roadbed foundation bed; constructing a reinforced concrete pile on the bottom surface of the roadbed foundation bed; pouring a reinforced concreter raft; pouring a bearing plate; backfilling water seepage soil at the two sides of the reinforced concrete raft and the bearing plate; starting to fill a foundation bed filler layer from the upper end surface of the bearing plate; constructing a water drainage ditch on a foundation of one side, away from the foundation bed, ofthe water seepage soil, enabling the water drainage ditch to communicate with the water seepage soil, draining underground water below and at the two sides of the reinforced concrete raft for enablingthe filler on the bearing plate to be in a dried state. The roadbed structure sufficiently integrates the integral structure of the pile and the raft with high filler replacement and water drainage limit to successfully solve the risk that expansive soil expands and arches upwards under action of saturated water, and to solve the problem that the foundation bed pumps mud.

Description

technical field [0001] The invention relates to the technical field of track subgrade structures, in particular to a construction method for a subgrade with high groundwater level and low fill and shallow excavation. Background technique [0002] Under the high groundwater level, low-fill and shallow-cut expansive soil subgrade of high-speed railway is generally replaced with permeable soil in the range of the subgrade bed, and the foundation is treated with pile-net composite foundation. This treatment measure can meet the subgrade settlement control requirements, but there are still some problems for high-speed railways with millimeter-level deformation requirements: some high-speed railways currently in operation have successively experienced some upturning diseases due to water absorption and expansion of expansive soil, and pile-net composite foundations have not Fully consider the anti-arching effect. Under the high groundwater level, the expansive soil is more likely ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem that the existing pile raft structure mentioned in the above-mentioned background technology is easy to cause roadbed diseases when it is applied to a high groundwater level area, and to provide a high groundwater level low filling shallow excavation expansive soil roadbed construction method

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