Model test device for the influence of double tunnel excavation on pile foundations that can realize multi-directional adjustment

Abstract

The invention provides a model test device for the effect of double tunnel excavation on pile foundations that can realize multi-directional adjustment, including: a frame, a double-line tunnel position control unit for adjusting the relative position of the double-line tunnel, and a double-line tunnel for simulating Two tunnel lining model elements, two tunnel excavation construction simulation elements for simulating double-track tunnel excavation, pile group model elements for simulating pile foundations, pile group pile tops for simulating loads on pile tops A concentrated load applying unit and an aluminum plate lifting unit for adjusting the lifting of the second aluminum plate. The invention can realize the influence of multi-directional adjustment of double-line tunnel excavation on the ground surface and adjacent pile foundations, and can also test the influence of tunnel crossing landslide construction on tunnel and surrounding soil under rainfall conditions, so as to achieve accurate measurement of tunnel crossing landslides The technical effects of tunnel lining deformation, landslide surface displacement, surface soil settlement and deep soil displacement caused by solid construction.

Description

technical field [0001] The invention belongs to the field of tunnel engineering in geotechnical and underground engineering, and in particular relates to a model test device capable of realizing multi-directional adjustment of the influence of double tunnel excavation on pile foundations. Background technique [0002] With the development of social economy and the increasing demand for urban rail transit, the construction conditions of underground tunnel projects have become increasingly complex, and more and more double-track tunnels have appeared in parallel. The shield method construction of the subway tunnel in the urban center with dense structures will inevitably cause the original initial ground stress balance to be broken and the soil surface to deform, which will easily cause the displacement and settlement of the adjacent pile foundation, and affect the bearing capacity of the adjacent pile foundation. The load will have an adverse effect, and even lead to a signif...

AI Technical Summary

Problems solved by technology

Most of the empirical formula methods use the empirical formula proposed by Peck to estimate the surface settlement values ​​caused by the excavation of the two tunnels separately and superimpose them to calculate the surface settlement value caused by the excavation of the double-track tunnel. However, the surface settlement value caused by the excavation of the double-track tunnel The settlement value is greater than the surface settlement value estimated by the superposition principle; the numerical simulation method is relatively mature, but there are still shortcomings: (1) need to use high-cost finite element software for analysis; (2) small changes in soil physical parameters It will have a great impact on the numerical simulation results, and it is difficult to obtain accurate soil parameters due to the limitation of geotechnical testing equipment.

On-site monitoring methods are limited by equipment and human observation factors. On-site test results have certain deviations. At the same time, on-site monitoring requires a certain amount of manpower and material resources. The on-site pre-embedded test components are very easy to be damaged during construction, thereby delaying monitoring and even getting errors. monitoring information

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