Highway subgrade widening structure

Abstract

The invention discloses a highway subgrade widening structure, which relates to the technical field of subgrade widening, and comprises a plurality of layers of newly-filled subgrades, a lime soil cushion layer, a plurality of layers of newly-filled subgrades and a pavement structure layer which are sequentially arranged from bottom to top, the structure further comprises geogrids laid between every two adjacent layers of newly-filled subgrades, geogrids laid in the middle of the lime-soil cushion layer, geogrids laid on the bottom face of the lowermost layer of newly-filled subgrade, vertical short pile bodies perpendicular to the loess stratum, and vertical long pile bodies perpendicular to the loess stratum. The pile tops of the vertical short pile bodies are tightly attached to the top face of the loess stratum. The pile tops of the vertical long pile bodies are tightly attached to the bottom face of the lime soil cushion layer. The pile bottoms of the vertical short pile bodies and the pile bottoms of the vertical long pile bodies are located in the loess stratum. The post-construction settlement of the new subgrade can be effectively controlled, the stability is ensured, and the stability of the old subgrade can also be ensured.

Description

technical field [0001] The invention relates to the technical field of roadbed widening, in particular to an expressway roadbed widening structure. Background technique [0002] With the rapid development of the economy, road transport is an important part of transportation, and the requirements for road transport construction are becoming more and more stringent. Some of the existing highways can no longer meet the needs of the actual transportation volume, and now in the design of engineering reconstruction and expansion, it is inevitable to encounter roadbed widening. According to the analysis of the operation situation of the completed reconstruction and expansion, the differential settlement is one of the main diseases of the widened roadbed, which has brought great economic losses. There are many technical problems in expressway roadbed widening project in loess area, and improper treatment will easily lead to longitudinal cracks in the road surface, uneven settlement...

AI Technical Summary

Problems solved by technology

This foundation treatment method cannot prevent subgrade settlement in some loess areas. At this time, the blind use of reinforced concrete piles and prestressed pipe piles and other rigid pile composite foundations will cause the reinforcement strength of the widened part of the foundation to be too large, making the road surface appear Reversed slope or concave shape will lead to deformation of the road surface and poor drainage, which will endanger driving safety

Therefore, in the expressway roadbed widening project in the loess area, it is necessary to effectively control the post-construction settlement of the new roadbed to ensure stability (based on the vertical pile directly acting under the geogrid and lime-soil cushion), and to ensure the stability of the old roadbed However, the current method of using reinforced concrete piles and prestressed pipe piles and other rigid pile composite foundations for roadbed widening cannot achieve both effective control of the post-construction settlement of the new roadbed, ensuring stability, and ensuring the stability of the old roadbed.

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