Construction method for rubble stone-ventilating board composite roadbed of expressway at permafrost area

Abstract

The invention relates to a construction method for a rubble stone-ventilating board composite roadbed of an expressway at a permafrost area. The method includes the steps that firstly, rubble stone is prepared, after a bottom cushion layer is detected to be qualified, the rubble stone is poured for filling at a time, and then filling shaping, leveling and padding, and static pressure rolling are conducted; gravels are poured on the rubble stone for filling, after leveling and static pressure rolling, a water-permeable geotextile is laid on a gravel layer, and a sand-gravel cushion and a geogrid are laid on the water-permeable geotextile, so that roadbed construction is completed; a high-strength waterproof film is laid on the top face of a roadbed, pouring formworks for ventilating boards are mounted, a reinforcement fabric is manufactured, transverse PVC ventilating pipes are arranged, pouring is completed, and after top galling, curing and demolding are conducted. By means of the construction method, the temperature of the top surface of the rubble stone roadbed can be lowered, and the convection heat exchange effect inside the roadbed is enhanced; after the ventilating boards are additionally arranged on the rubble stone layer, the upper temperature of the rubble stone layer is lowered through the ventilation effect, the temperature difference between the top and the bottom of the rubble stone layer is increased, and the convection heat exchange effect of the rubble stone layer is enhanced.

Description

technical field [0001] The invention relates to a roadbed construction method, in particular to a construction method for a highway flake stone-ventilation plate composite roadbed in permafrost regions. Background technique [0002] Highway construction in the permafrost region has a relatively strong thermal disturbance to the subgrade. Due to the construction of the subgrade, the water and heat conditions of the permafrost have been changed, resulting in the redistribution of water and heat, which has accelerated the degradation process of the permafrost. Preventing large deformation of the subgrade and ensuring the strength and stability of the subgrade are the keys to highway engineering construction. The uneven subsidence caused by the decline of the upper limit of permafrost at the lower part of the roadbed is the main way of road damage. In the past, when dealing with these roadbed diseases, there was a guiding ideology of over-reliance on increasing thermal resistanc...

AI Technical Summary

Problems solved by technology

The uneven subsidence caused by the decline of the upper limit of permafrost at the lower part of the roadbed is the main way of road damage. In the past, when dealing with these roadbed diseases, there was a guiding ideology of over-reliance on increasing thermal resistance to protect frozen soil in the design scheme, and frozen soil The management method of the project is relatively simple

A large number of engineering practices at home and abroad have proved that measures to increase thermal resistance, such as increasing the height of embankments and using insulation materials, can delay the melting of permafrost, but cannot fundamentally improve the trend of increasing heat storage in roadbeds year by year.

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