Stable and rapid jacking construction method for box culvert under large excavation face

Abstract

The invention discloses a stable and rapid jacking construction method for a box culvert under a large excavation face. The stable and rapid jacking construction method comprises the following steps that (1) an auxiliary beam system is converted; (2) construction surveying and setting-out are conducted; (3) earthwork is mechanically excavated in a layered and segmented manner; (4) an extension sliding plate is constructed; (5) steam curing of the sliding plate is conducted; (6) the box culvert is jacked, and deviation is controlled; (7) the auxiliary beam is dismantled, and a ballast is recovered; (8) checking and accepting are conducted. According to the method, earth cutting and jacking are creatively separated, excavation and transportation of large-area jacking soil of all the box culverts are conducted firstly, uneven friction resistance generated by soil to the box culverts in the jacking process is eliminated, then the extension length of the sliding plate is increased till the box culverts are jacked to the final position, by means of the design advantages that the bearing capacity is high after the sliding plate are extended and steel sliding rails are arranged, continuous operation of jacking construction is achieved, deviation is corrected in time, and jacking is completed smoothly. The construction technology has the advantages of being high in construction efficiency, low in cost, safe, environmentally friendly and the like.

Description

Technical field: [0001] The invention relates to a box culvert jacking construction method, in particular to a stable and fast jacking construction method for a box culvert under a large excavation face. Background technique: [0002] In order to meet the needs of urban development and facilitate people's travel and cargo transportation, some large-scale passenger and freight railway lines have been erected from the wild suburbs to the city. At the intersection of the railway and the existing urban road, it is necessary to use the introduction of the viaduct or the underpass, that is, box culvert jacking, to complete the transition between the two types of roads. [0003] Box culvert jacking is a relatively mature railway construction technology. At present, the traditional box culvert jacking construction technology is digging soil and jacking at the same time. The following problems exist in the construction process: [0004] 1. The traditional box culvert jacking constru...

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Problems solved by technology

[0006]3. The traditional jacking construction is to excavate the soil and jacking at the same time, but the depth of one-time drilling should not be too long, each time is 0.4m-0.8m

When the box culvert is constantly advancing during the jacking process, the equipment needs to continuously increase the jacking iron to press the soil to ensure the smoothness of the road. At this time, the muck truck needs to wait for the road to be clear before entering the box culvert to unearth, which cannot form a coherent The unearthed work affects the unearthed efficiency, and the mechanical intermittent time is also prolonged, the construction efficiency is low, the construction time is long, and the labor and equipment input costs are correspondingly increased.

[0007]4. In the traditional box culvert jacking construction, the soil friction force is not uniform during the jacking process with soil, resulting in excessive deviation of the box culvert, which is prone to off-axis movement , during the jacking process, the front end of the box culvert enters the soil, and when the center of the box culvert leaves the slide plate, the box culvert enters the elastic foundation from the rigid slide plate. When the ability to resist the downward pressure of the box culvert is lost, the jacking equipment at the back will push the box culvert deeper and deeper, forming a "head tie"; the accumulated soil during the bottom of the box culvert will accumulate more and more with the jacking process. If the box culvert is not cleaned or corrected in time, the box culvert will have a tendency to jack up, and the box culvert will gradually rise up, eventually forming a "lift-up"; in addition, due to the uneven excavation on both sides of the box culvert, there is over-excavation on one side. Under the premise of the jacking force, the box will be continuously shifted towards the over-excavation, or the two sides of the box culvert will be subjected to uneven jacking force during the jacking process, resulting in one side being tilted, and the deviation will also occur

At present, there are no effective solutions to the problems of "tie head", "head up" and "offset" in the traditional box culvert jacking construction, which seriously affect the construction quality and efficiency

[0008]5. For projects where the construction site is limited or the jacking operation is completed in a small construction area, the foundation pit occupies a large area due to slope excavation, occupying The construction site has a large area, and the unearthed horse path is close to the red line of land acquisition after grading, so the remaining usable area is not enough for earthwork transportation and construction vehicles to enter, which is not conducive to earthwork operations

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