Calculation method for dynamic additional stress of roadbed under load effect of vehicles

A technology of additional stress and vehicle load, applied to roads, roads, road repairs, etc., can solve problems such as the periodicity of vehicle loads that do not consider the layered characteristics of the roadbed and pavement

Inactive Publication Date: 2019-03-26
CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] At present, there are few studies on the internal dynamic additional stress of the subgrade pavement system under the action of vehicle loads at home and abroad, and most of them do not consider the layered characteristics of the subgrade pavement and the periodicity of vehicle loads.

Method used

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  • Calculation method for dynamic additional stress of roadbed under load effect of vehicles
  • Calculation method for dynamic additional stress of roadbed under load effect of vehicles
  • Calculation method for dynamic additional stress of roadbed under load effect of vehicles

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Experimental program
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Embodiment

[0111] In this embodiment, the present invention is illustrated by taking the section near the K47+795 pile number of the Shunde Bijiang to Zhongshan Shaxi section of the Taiao Expressway to verify the correctness of the dynamic additional stress model of the multi-layer subgrade pavement system under the action of vehicle loads.

[0112] 1. Physical parameters of in-situ and indoor tests

[0113] The dynamic load on the road surface is 500kN, which is converted into a road surface load of 50kPa, and the driving speed is 10m / s. It is assumed that the safe distance between the two vehicles is 100m. The physical parameters of each layer of the test layer are shown in the table below.

[0114] Table 1 The physical and mechanical parameters of each layer of the research section

[0115] Material

Thickness / m

Density / (kg.m 3 )

Modulus of elasticity / Mpa

Poisson's ratio

Base fill

4.0

1500

2300

0.30

sand cushion

0.5

1800

2...

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Abstract

The invention discloses a calculation method for the dynamic additional stress of the roadbed under the load effect of vehicles. The calculation method includes the following steps: (1) according to actual conditions of the roadbed and surface of a road, establishing a two-dimensional elastic layered body model, and transforming stress and displacement in an elastodynamic control equation into state vectors under modal coordinates; (2) separating and eliminating a time variable in a dynamic additional stress expression; (3) subjecting the state vectors to Laplace transformation, and acquiringa stiffness matrix of layered foundations by a transfer matrix method; (4) according to initial conditions and boundary conditions, establishing a dynamic additional stress quantitative model of a layered roadbed and road surface system; (5) subjecting the model to Laplace inverse transformation by a Durbin method to obtain the dynamic additional stress of the roadbed under the load effect of thevehicles. The calculation method for the dynamic additional stress of the roadbed provided by the invention is suitable for selection of road and rail roadbed fillers and the structural combination design of the roadbed.

Description

technical field [0001] The invention relates to a calculation method for the dynamic additional stress of the subgrade under the action of vehicle load. Background technique [0002] Under the action of vehicle load, the subgrade and pavement system will experience dynamic effects such as vibration and impact on its internal structure. The structural stress due to the dynamic stress effect is called dynamic additional stress. If the subgrade system is in operation and the dynamic additional stress generated by the vehicle load is greater than the critical dynamic stress of the soil inside the subgrade, the subgrade will produce cumulative settlement deformation, which will lead to cracking, rutting and other diseases on the road surface. Therefore, it is of great significance to study the distribution law of the dynamic additional stress of the subgrade under the action of vehicle load for the selection of subgrade filler and the design of subgrade structure combination. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E01C23/01
CPCE01C23/01
Inventor 韦秉旭冯学茂刘雄范峥
Owner CHANGSHA UNIVERSITY OF SCIENCE AND TECHNOLOGY
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