Construction method for bottom protection of long mouth of ultra-long closure embankment in silt fine sand deep overburden layer

Abstract

The invention discloses a construction method for a fine sand ultra-long interception embankment closure gap bottom guard with a deep covering layer. The construction method comprises the steps as follows: 1, determining the positions of closure gaps; 2, pre-occupying the positions of the closure gaps by an embankment from one side of a river bed, occupying the positions of the closure gaps by the embankment and occupying all the positions of the closure gaps; 3, protecting the part below the elevation of the bottom guard of the closure gaps in the slope surfaces on the upstream side and the downstream side of the embankment occupying all the positions of the closure gaps by boulders; 4, after protecting, reversely excavating away embankment materials pre-occupying the part above the elevation of the bottom guard of the closure gaps, and protecting the top surface of the excavated embankment in the excavating process by the boulders; 5, after excavating all the embankment materials occupying the part above the elevation of the bottom guard of the closure gaps, building an embankment wrapping head on the side; and 6, pre-occupying the positions of the closure gaps by the embankment from the other side of the river bed and building the embankment wrapping head on the side. The construction method is reasonable in design, low in construction difficulty, low in dumping intensity, high in construction efficiency, short in construction period, economic and practical, achieves the purpose of scientific interception, and is convenient for popularization and application.

Description

technical field [0001] The invention relates to the technical field of riverbed closure in water conservancy and hydropower projects, in particular to a construction method for protecting the bottom of a dragon mouth with an ultra-long closure embankment and a deep covering layer of silt and fine sand. Background technique [0002] The upstream and downstream cofferdams of the Yellow River Haibowan Water Conservancy Project are located in the bend of the Yellow River. The valley is about 540m wide and is an asymmetrical wide valley. The river bed elevation is 1064.00m-1066.50m; 0.5-2.5m, the width of the main channel is about 400m; the valley area is the alluvial landform type of the Yellow River, mainly floodplain. The surface layer of the river bed is newly accumulated fine sand and silt, loose to slightly dense, and the lithology of the formation is mainly silt and fine sand, interbedded with gravel, medium coarse sand and cohesive soil interlayer and lens body Quaternary...

AI Technical Summary

Problems solved by technology

Under the geological conditions of low anti-scouring flow rate and deep overburden layer, severe erosion will be formed on the dragon mouth, which will make closure more difficult. , the water level is shallow, it is difficult to use boats or set up trestles to throw interception materials to protect the bottom of the dragon mouth, and the throwing intensity is also high

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