Particulate body protecting structure for partial scouring of head of spur dike or bridge pier and construction method thereof

Abstract

The invention discloses a particulate body protecting structure for partial scouring of the head of a spur dike or a bridge pier and a construction method thereof. The protecting structure is mainly applied to protection of partial scouring of the head of the spur dike or the bridge pier. For protecting partial scouring of the bridge pier, the structure is an annular particulate body gravel layerlaid on the riverbed around the bridge pier; for protecting partial scouring of the head of the spur dike, the structure is a U-shaped annular particulate body gravel layer laid on the riverbed aroundthe spur dike. The particle size of gravel is multiple times the median size of incipient sediment under the flow condition encountered once twenty years locally. The construction method comprises the steps that 1, the construction position is determined under the tide stabilizing condition; 2, gravels are laid on the designated riverbed in sequence from the downstream part to the upstream part,wherein firstly, gravels of the range of 1.5-2.5 m are laid within the range of 0-6 m around the spur dike and the bridge pier, and then the periphery is paved on the basis of the slope ratio being 1:3. By means of the partial scouring mechanism of the head of the spur dike and the bridge pier, when a scouring pit of the head of the spur dike and the bridge pier is not balanced, the gravel layer of the certain thickness and range is laid around the spur dike and the bridge pier, and therefore partial scouring is well restrained.

Description

technical field [0001] The invention belongs to the protection field of bridge piers and spur dike heads, and in particular relates to a granular protection structure and a construction method thereof for local scour of bridge piers and spur dike heads. Background technique [0002] Local scour around the bridge piers and spur head is an unavoidable problem. In the river, the existence of piers and spur dikes will change the water flow structure nearby, making the turbulence around the head of the pier and spur dike stronger, and a large-scale vortex system will be generated around the pier and spur dike head, and the center of the vortex will form a negative pressure suction. The sediment on the bed surface is carried downstream, causing the scour of the bed surface around the pier and spur head. Historical experience shows that scour will pose a huge threat to the stability of structures. [0003] Theoretically, the scouring action between the water flow and the pier can...

AI Technical Summary

Problems solved by technology

[0007] However, the traditional local scour protection measures for bridge piers and spur dike heads have certain application limitations and are expensive and difficult to construct.

For example, in the riprap protection commonly used in engineering practice, the sediment at the bottom of the riprap is easily washed away, which will cause the position of the riprap to move, thereby weakening the protective effect

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