High fill subgrade connection method

Abstract

The invention discloses a high fill road section connection method, comprising the steps of: conducting bored pile (12) construction vertically at a side slope of an old subgrade (1), connecting multiple bored piles (12) into a vertically continuous bearing platform by means of a reinforced concrete supporting beam (11), the top surface of which is paved with a hardcore bed (10), and carrying out retaining wall (9) construction on the hardcore bed, when the retaining wall strength reaches over 75% of a designed strength level, performing cut slope (5) and step (6) excavation construction to the old subgrade slope, implementing filler (7) filling layer by layer and layering compaction, and finally paving newly connected wide pavement (4). The method of the invention restrains lateral deformations of a new subgrade (2) by means of various supporting and retaining structures, and opposes vertical deformations caused by various loads through a foundation reinforcing structure formed by the bored piles (12) and the reinforced concrete supporting beam (11), thus reaching the purposes of a stable overall structure and usage requirement satisfiable deformations.

Description

technical field [0001] The invention belongs to the technical field of roadbeds and railways, and mainly relates to a splicing method for high-filling roadbeds. Background technique [0002] At present, in highway and railway subgrade reconstruction and expansion projects, the main schemes adopted are: double-sided splicing, single-side widening and separated subgrade. [0003] Double-sided splicing has the advantages of less land occupation, large traffic capacity, and cost savings. It has been fully applied in the reconstruction and expansion of expressways in plain micro-hilly areas and some mountainous areas. However, the original expressway was limited by the design guidelines and economic conditions at that time, and there were many high-fill road sections, so it was difficult to implement the double-sided widening method. [0004] figure 1 Shown is a commonly used high-fill embankment double-sided widening technology. This widening technology is to remove the plowi...

AI Technical Summary

Problems solved by technology

This widening technology is based on the above-mentioned technical scheme, and by setting up inclined retaining walls 9 on the downslope, it achieves the purpose of saving land, shortening the construction period, and reducing the difficulty of compacting some filling layers. However, the foundation treatment project The reduction of the amount is not obvious, and there is also the additional settlement effect of the settlement of the new roadbed 2 on the old roadbed 1. It is difficult to ensure that the old road surface does not crack when the filling is high.

[0006] Since it is difficult to avoid the influence of the subsidence settlement of the new widened subgrade on the old road when the above two kinds of high fill are spliced, combined with the current design concept of safety and environmental protection, it is advisable to use bridges for expansion when splicing the original high fill road section, but the old road subgrade and pavement comprehensive Due to the large difference in stiffness between the body and the bridge structure, uneven settlement will seriously affect driving safety, the original old road part also needs to be excavated and replaced with a bridge

Although this reconstruction method has completely solved the splicing problem of high fill, the cost is high, the construction is complicated, the maintenance is difficult, and the implementation is difficult.

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