A roadbed concrete subgrade bed structure and construction method

Abstract

The invention discloses a roadbed concrete bed structure and a construction method. The roadbed concrete bed structure is provided with a plurality of sections of concrete beds and ballastless tracks arranged on the concrete beds, wherein each concrete bed is divided into a C35 concrete layer, a C20 concrete layer, 5% cement mixed graded broken stone layer and a packing layer from the top down sequentially; the ballastless tracks are laid on the concrete beds through a plurality of sections of base plates; an expansion joint is arranged between every two adjacent concrete beds; the expansion joints are fit with gaps between adjacent base plates; and each concrete bed is aligned to one base plate correspondingly. Free extension of bed concrete and the stability in a freezing and thawing state in an alpine region can be ensured, and a situation that no geometrical states of the ballastless tracks are changed due to temperature change can be finally guaranteed.

Description

technical field [0001] The invention relates to a subgrade concrete foundation bed structure and a construction method, which are mainly used in passenger dedicated line projects in alpine regions. Background technique [0002] The CRTSⅢ pre-tensioned slab ballastless track of the Liaoning section of the Beijing-Shenyang Passenger Dedicated Line was first popularized and adopted in passenger-only projects in alpine regions. The line is located in the cold region of Northeast China, and it is difficult to prevent frost heave for the subgrade, so anti-frost measures must be taken. Therefore, it is necessary to control the construction quality of the subgrade concrete to fundamentally solve the impact of frost heave on subgrade settlement. [0003] However, in the prior art, due to the unreasonable structure of the subgrade concrete bed, and the construction method did not take into account the constraints of various conditions, especially the treatment of expansion joints in t...

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Problems solved by technology

[0003] In the prior art, due to the unreasonable structure of the subgrade concrete bed, and the construction method did not take into account the constraints of various conditions, especially the treatment of expansion joints in the bed, the current usual treatment method is to use Insert the dowel bar before setting, and then install the waterstop after the C35 concrete layer is poured to the installation position of the waterstop

This method not only destroys the integrity of the end of the concrete foundation bed, but also makes it difficult to ensure that the dowel bars are at the same horizontal line and stable in relative position, let alone the fixed quality of the movable end of the dowel bars so that the dowel bars can fully function as telescopic force transmission. the role of

However, after the C35 concrete layer is poured to the installation position of the waterstop, the installation of the waterstop cannot effectively control the line shape of the waterstop, and it is difficult to play the role of waterstop.

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