CN-121428885-B - Construction method of road subgrade in permafrost region with light weight and hydrothermal regulation and control

CN121428885BCN 121428885 BCN121428885 BCN 121428885BCN-121428885-B

Abstract

The invention discloses a construction method of a road subgrade in a permafrost region, which takes light weight and hydrothermal regulation into consideration, wherein a subgrade filling body comprises a compact bearing layer, a core troposphere and a lower sealing layer which are sequentially arranged from top to bottom, the core troposphere is formed by stacking broken stones, the total height of the subgrade filling body is 1.0-1.5 m, the thickness of the core troposphere accounts for 30% -50% of the total height, the slope rate of a subgrade slope exceeds 1:3, a slope body health monitoring system is arranged in the slope structure, and comprehensive drainage systems formed by a slope drainage device, an intelligent lifting drainage device and a regulation evaporation device are constructed at two sides of the subgrade filling body. The invention can reduce the roadbed thawing deformation, keep permafrost stable, prolong the service life of the highway and protect the ecological environment.

Inventors

GAO FENG
GAO LIANG
LIU HONGYING
ZHANG JINBAO
QI SHENGBAO
CHEN XIANGQING
ZHOU SHIXUE
XIONG HONGLING
Shen xiaochang
LIU QIANG

Assignees

长沙理工大学
重庆大学

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (8)

1. A construction method of a road subgrade in a permafrost region, which takes light weight and hydrothermal regulation into consideration, is characterized by comprising the following steps: The method comprises the steps of S1, constructing a roadbed filling body (1), wherein the roadbed filling body comprises a lower sealing layer (8), a core troposphere (7) and a compact bearing layer (6) which are sequentially arranged from bottom to top, the core troposphere adopts gravels with the particle size of 30-60 mm to be piled up to form a ventilation channel with the porosity of 30-40%, the compact bearing layer and the lower sealing layer adopt gravel materials, the compaction degree of the gravel materials is more than or equal to 96%, the total height of the roadbed filling body is 1.0-1.5 m, the thickness of the core troposphere is 30-50% of the total height, and the lower sealing layer, the core troposphere and the compact bearing layer are sequentially filled from bottom to top during construction; S2, constructing a roadbed slope (2), wherein vent holes which are communicated with the ventilation channels and the outside atmosphere are formed in the roadbed slope, the slope rate of the roadbed slope exceeds 1:3, the average flow rate of the section of the slope water collection is smaller than the allowable non-flushing flow rate of the slope material, a slope body health monitoring system is arranged in the slope structure, and the slope body health monitoring system comprises a temperature sensor array (14), a volume water content sensor array (15), a deep soil displacement sensor array (16), a surface crack meter (13) and an environment monitoring sensor (19) which are distributed according to a space three-dimensional grid; s3, constructing a comprehensive drainage system, wherein the comprehensive drainage system comprises a side slope drainage device, an intelligent lifting drainage device and a regulation evaporation device, the side slope drainage device comprises a side slope drainage layer (11), a drainage blind ditch (12) buried in the side slope, a water interception open ditch (9) arranged on the side slope shoulder and a water collection open ditch (10) arranged on the side slope foot, the side slope drainage layer is paved by gravel, and an outlet of the ventilation hole is arranged on the side slope drainage layer, so that the side slope drainage layer has ventilation and shallow water seepage drainage functions; the intelligent lifting drainage device comprises a water collecting well (20) for connecting the water collecting channel, a submersible pump set (21) arranged in the water collecting well, a pressure conveying pipeline (22) for connecting the submersible pump set and the evaporation tank (4) and an intelligent control system (23), wherein the intelligent control system comprises a liquid level sensor and a solar photovoltaic power generation system (24), the storage regulation evaporation device comprises the evaporation tank (4) which is arranged far away from a roadbed filling body, the design height of the bottom of the evaporation tank exceeds the upper limit of frozen soil for many years by 1m, the horizontal distance between the edge of the evaporation tank and the roadbed slope foot is more than 100m, and the tank body comprises a base layer, a secondary impermeable layer (27), a base layer, a waterproof layer and an anti-seepage layer (27), A main impermeable layer (26) and a protective layer (25).
2. The construction method of the road subgrade in the permafrost region, which combines light weight and hydrothermal regulation and control according to claim 1, is characterized in that the temperature sensor array is used for monitoring the temperature field changes of soil bodies with different depths, the volume water content sensor array is used for monitoring the water distribution dynamics with different depths, the deep soil displacement sensor array is used for monitoring the deformation and slippage in the deep soil, all sensor signal cables are finally gathered to a data acquisition box (17) of the toe of a slope, and the data acquisition box is powered by a side slope solar power supply system (18).
3. The construction method of the road subgrade in the permafrost region, which combines light weight and hydrothermal regulation and control according to claim 2, is characterized in that the surface crack meter (13) is arranged on the surface of a slope, the environment monitoring sensor (19) is arranged on the slope foot, the surface crack meter is used for monitoring the development condition of cracks on the slope and the displacement of deep soil, and the environment monitoring sensor is used for collecting rainfall, snowfall and solar radiation data in real time.
4. The construction method of the road subgrade in the permafrost region, which combines light weight and hydrothermal regulation and control, according to claim 1, is characterized in that the water collecting well adopts a reinforced concrete cast-in-situ structure and is designed to be underground or semi-underground.
5. The construction method of the road subgrade in the permafrost region, which combines light weight and hydrothermal regulation and control according to claim 1, is characterized in that the lift of the submersible pump set exceeds the water flow to the ground and overcomes the head loss generated by the water collecting channel conveying, and meanwhile, the submersible pump set adopts a backup or alternate operation mode.
6. The construction method of the permafrost region highway subgrade taking light weight and hydrothermal regulation into account according to claim 1, wherein the evaporation pond is constructed by utilizing a road area excavation region.
7. The construction method of the road subgrade in the permafrost region, which combines light weight and hydrothermal regulation and control, according to claim 1, is characterized in that the effective regulation volume of the evaporation pond is determined according to the design storm path flow of the catchment region.
8. The construction method of a permafrost region highway subgrade with light weight and hydrothermal regulation and control according to claim 1, characterized in that the base layer is a flattened and compacted foundation, and the secondary impermeable layer adopts a thickness of not less than 0.75 m and a permeability coefficient The compacted clay layer is cm/s, the main impermeable layer is an HDPE geomembrane with the thickness not less than 1.5 mm, and the protective layer is a non-woven geotextile.

Description

Construction method of road subgrade in permafrost region with light weight and hydrothermal regulation and control Technical Field The invention relates to a roadbed structure of a permafrost region, in particular to a construction method of a roadbed of a permafrost region, which takes light weight and hydrothermal regulation into consideration. Background Stabilization and durability of highway foundations in permafrost regions (such as the Qinghai-Tibet plateau) is a central challenge in the construction of cold-zone traffic infrastructure. Under the background of continuous warm and humidification of plateau climate and aggravation of engineering activities, the hydrothermal balance state of the original frozen soil stratum is disturbed, so that the risk of diseases such as freeze thawing subsidence, cracking and the like of the road subgrade built on the road subgrade is increased, and the traffic safety and service life of the road are restricted. The prior art has the following defects when processing roadbed engineering problems in permafrost areas: 1. The structural measures are not coordinated with hydrologic thermodynamic protection, the existing scheme is not coordinated with hydrologic thermodynamic protection, the stability is guaranteed due to the fact that the structural size and weight are excessively increased, the additional load problem caused by the structural measures is ignored, or the partial temperature control is biased, but an effective surface water dredging method is lacked, and the thermal erosion is caused by water infiltration. 2. The technical feasibility and the long-term durability are insufficient, the construction process of a part of schemes is complex, the requirements on materials and equipment are high, the implementation is difficult under the severe natural conditions of a plateau and the background of weak infrastructure, the evolution rule of the long-term performance of new materials and new structures under the action of freeze thawing circulation is not clear, and the durability risk exists. 3. The design system is insufficient, the ecological compatibility is poor, the design range of most technical schemes is limited to roadbed bodies, the hydrologic ecological comprehensive planning starting from the whole road domain system is lacking, and engineering safety and ecological environment protection cannot be organically combined. Therefore, a novel roadbed structure and a design method thereof are urgently needed, wherein the novel roadbed structure can simultaneously realize the light weight of the roadbed and the active drainage of surface water and has the convenience of plateau construction and the ecological friendliness. Disclosure of Invention Aiming at the problems of heavy roadbed weight in permafrost region, increased thawing and sinking, crack expansion, increased side slope sliding risk and the like caused by surface thawing water erosion of roadbed, the invention aims to provide a method for constructing a permafrost region highway roadbed, which combines light weight and hydrothermal regulation. In order to solve the technical problems, the technical scheme adopted by the invention is that the construction method of the road subgrade in the permafrost region, which takes light weight and hydrothermal regulation into consideration, comprises the following steps: The method comprises the steps of S1, constructing a roadbed filling body, wherein the roadbed filling body comprises a lower back cover layer, a core troposphere and a compact bearing layer which are sequentially arranged from bottom to top, the core troposphere adopts crushed stones with the particle size of 30-60 mm to be piled up to form a ventilation channel with the porosity of 30-40%, the compact bearing layer and the lower back cover layer adopt gravel materials, the compaction degree of the gravel materials is more than or equal to 96%, the total height of the roadbed filling body is 1.0-1.5 m, the thickness of the core troposphere accounts for 30-50% of the total height, and the lower back cover layer, the core troposphere and the compact bearing layer are sequentially filled from bottom to top during construction; S2, constructing a roadbed slope, wherein vent holes which are communicated with the ventilation channels and the outside atmosphere are formed in the roadbed slope, the slope rate of the roadbed slope exceeds 1:3, the average flow rate of the section of the slope water collection is smaller than the allowable non-flushing flow rate of the slope material, and a slope body health monitoring system is arranged in the slope structure; And S3, constructing a comprehensive drainage system, wherein the comprehensive drainage system comprises a side slope drainage device, an intelligent lifting drainage device and an adjustable evaporation device, the side slope drainage device comprises a side slope drainage layer, a drainage hidden ditch buried in the side slope, a water