Ballastless track coarse-grain salty soil embankment structure considering acute air temperature influence and construction method

Abstract

The invention provides a ballastless track coarse-grain salty soil embankment structure considering acute air temperature influence and a construction method, so that a high-speed railway ballastlesstrack arching and settlement deformation control target is achieved, the situation that water and salt are transferred and gathered to the top of a roadbed is avoided, and the technical defects existing when coarse-grain salty soil serves as high-speed railway embankment padding are effectively overcome. The embankment structure is composed of a foundation bottom separation layer, an embankment body, a foundation bed bottom layer lower structural layer, a foundation bed separation layer, a foundation bed bottom layer upper structural layer and a foundation bed surface layer, all of which are sequentially laid from bottom to top above a foundation. The embankment body and the foundation bed bottom layer lower structural layer are constructed through the coarse-grain salty soil, the salt expansion coefficient of the coarse-grain salty soil is not larger than 0.01, and the foundation bed bottom layer upper structural layer and the foundation bed surface layer are filled with non-salty soil. The burial depth of the foundation bed separation layer is not smaller than the depth of an acute air temperature influence layer. The depth of the acute air temperature influence layer is the depth at which atmosphere air temperature influence is quite remarkable or salt expansion deformation is acute.

Description

technical field [0001] The invention relates to the technical field of high-speed railway ballastless track embankment, in particular to a ballastless track coarse-grained saline soil embankment structure and a construction method considering the influence of severe air temperature. [0002] technical background [0003] Saline soil is a general term for a type of soil with different degrees of salinization, which is widely distributed in arid, semi-arid and coastal areas of various countries. Saline soil generally includes coarse-grained saline soil and fine-grained saline soil. Coarse-grained saline soil has better mechanical properties and has been used as embankment filler in expressway construction; but as high-speed railway embankment filler, especially The application of ballastless track embankments is extremely rare worldwide. [0004] In saline soil areas, the high-speed railway line inevitably passes through the saline desert area, and the high-quality embankment ...

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Problems solved by technology

[0004] In saline soil areas, the high-speed railway line inevitably passes through the saline desert area, and the high-quality embankment fillers without salt along the line are extremely scarce, and the long-distance transportation of high-quality embankment fillers without salt or rocks will increase the project investment dramatically. However, , saline soil has adverse engineering characteristics such as salt swelling, dissolution, erosion, etc., which can easily cause arching or subsidence on the top of the embankment to exceed the limit

[0005] The Chinese invention patent of notification number CN106555368B discloses the high-speed railway reinforcement structure in the saline soil area. This patent uses saline soil with different salinity to respectively fill the upper structural layer of the subgrade bed bottom layer, the lower subgrade layer of the subgrade bed bottom layer and the subgrade body, in order to Solve the problem of subgrade dissolution and salt swelling in saline soil, but its technical deficiency is that the upper limit of the salt content of the upper structural layer of the subgrade bed layer, the lower structural layer of the subgrade bed layer, and the subgrade body filler is a fixed value, which fails to consider The impact of filler gradation, and freeze-thaw cycles (especially low temperature effects) can easily lead to the migration and accumulation of salt to the upper part of the roadbed. It can be seen that the patent does not consider the impact of severe temperature

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