Method for repairing pile foundation and scour pit underwater

Abstract

The invention relates to a method for repairing a pile foundation and a scour pit underwater. The method includes the following steps that (1), a steel plate pile cofferdam is adopted for conducting construction around the local scour pit of a pier needing to be repaired; (2), a concrete cushion layer is laid within the range 2 m away from the pier; (3), the condition that the pier is damaged dueto scouring and corrosion is checked, and the pier is repaired firstly; (4), natural backfill soil is packed in the scour pit; (5), multiple stones are packed in the scour pit; and (6) ordinary Portland cement mortar is laid flatly on a macadam grouting protection layer, an RPC material is packed in the portion at the depth 15% of the remaining depth of the scour pit, an RPC layer is formed untilthe RPC layer is flush with the bottom face of a riverbed, and a soil layer is backfilled in the portion, around the RPC layer, in the scour pit. By the adoption of the method, the effect that the scoured and damaged pier foundation and the scour pit can be repaired, the bearing capacity of the original structure is improved, the service life of the structure can be prolonged by the adoption of the RPC material, and maintenance cost is saved.

Description

technical field [0001] The invention relates to a method for underwater repairing of pile foundations and scour pits, and belongs to the technical field of repair design of local scour pits of bridge piers. Background technique [0002] In recent years, bridges such as Lianyang Bridge, Bahe Bridge in Xi'an, Bahe Super Bridge, Gaoping Bridge in Taiwan and Changfeng Bridge in Zhejiang have been damaged by water, all of which are caused by the acceleration of water flow through the cylinder of the pier, causing the flanks of the flat-headed pier to be damaged. create a higher flow rate. A static surface is formed where the water flow approaches the pier, and a vertical pressure gradient is formed along the static surface of the pier. This pressure gradient causes downward water flow at the front of the pier, thus forming a scour pit, which reduces the bearing capacity of the pier column and is prone to overturning hazards. Therefore, after the scour pit is formed, how to repa...

AI Technical Summary

Problems solved by technology

[0003] Existing conventional methods for repairing scour pits include riprap anti-scouring and filling concrete mold bag protection, etc. riprap protection is still the most widely used protection form for large and medium-sized bridge piers. It has the advantages of convenient material acquisition, simple construction, and adaptability to terrain changes. and other advantages, but its integrity is poor, the maintenance cost and workload are large, and the maintenance cycle is short

The disadvantage of concrete mold bag protection is that the construction is more complicated, and the protection effect is not very good when the underwater terrain is steep, especially when the water depth is large and the water flow is fast, the underwater construction is difficult, and the ability to adapt to the deformation of the river bed after construction is relatively weak. Poor, vulnerable to brushing at the lower edge

These traditional methods have many deficiencies, are not perfect, have certain limitations in use, and cannot completely solve the problem of scour pits

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