Construction method for treating adjacent existing railway line soft soil foundation and roadbed structure thereof

Abstract

The invention discloses a construction method for treating an adjacent existing railway line soft soil foundation and a roadbed structure thereof. The construction method comprises the steps of leveling the site, and longitudinally constructing a plurality of rows of rigid CFG piles along the line in the slope toe area of the side, away from an existing railway line, from a safety limit part to a designed newly-built roadbed; longitudinally constructing a plurality of rows of flexible jet grouting piles along the line in the slope toe area of the side, close to the existing railway line, from the safety limit part to the designed newly-built roadbed; longitudinally paving a mattress layer along the railway line above the rigid CFG piles and the flexible jet grouting piles and at the top of a soft soil layer; and paving a roadbed above the mattress layer according to the design. According to the construction method and the roadbed structure, the roadbed bearing capacity is effectively improved, the post-construction settlement of the roadbed is reduced, the stability of the soft soil foundation is guaranteed, and the negative impact to the safe operation of the existing railway line is avoided; and the roadbed reinforcement structure is simple in form, good in stratum adaptability, reasonable in technology, and economic in cost, and has relatively high popularization and application value.

Description

technical field [0001] The invention relates to the field of geotechnical engineering, in particular to a construction method for treating soft ground adjacent to an existing line and a subgrade structure thereof. Background technique [0002] In order to ensure the safety of high-speed traffic, high-speed railways have extremely high requirements on the post-construction settlement of the subgrade. The post-construction settlement of the ballastless track subgrade should generally not exceed 15mm, and the differential settlement of the bridge or tunnel transition section should not exceed 5mm. When building a high-speed railway in a soft soil area and due to station yard or other conditions, roadbed must be used to pass through, reasonable foundation treatment measures need to be taken to make the post-construction settlement of the roadbed within the control standard. Generally, the soft soil foundation has a bottom-to-top structure including a hard soil layer, a soft soil...

AI Technical Summary

Problems solved by technology

When the CFG pile network foundation treatment is carried out on the soft soil foundation of the new railway, because the height of the CFG pile machine equipment is more than 24m, the center of gravity is high, the self-stability is poor, and it needs to be moved frequently during the construction process, it cannot be effectively protected, and overturning invades the safety of existing lines. Possibility of boundary limits will pose a danger to the safe operation of existing lines; in addition, after each construction is completed, construction equipment must be withdrawn to a safe distance, which will greatly prolong the construction period and increase project costs

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