A concrete crack-resistant construction method for the main structure of an open-cut and cast-in-place tunnel

Abstract

The invention belongs to the technical field of tunnel construction, and in particular discloses an anti-cracking construction method for concrete of the main structure of an open-cut and cast-in-place tunnel, which includes the steps of dividing the pouring length, the preparation of crack-resistant concrete, the temperature control step of mold entry, and the construction process control step . The present invention aims at the main contradiction of shrinkage and cracking of the concrete of the main structure of the open-cut and cast-in-place tunnel, from the control of the temperature of the anti-crack concrete (the adiabatic temperature rise of the anti-crack concrete, the mold entry temperature, the maximum temperature rise, the temperature difference between the inside and the outside, the center temperature drop rate, Formwork removal or removal of external insulation measures (temperature difference) and shrinkage deformation (7d self-generated volume deformation and 28d deformation of crack-resistant concrete), put forward the crack resistance control index and implementation plan, and formed a customized package for the main structure of different parts The technical scheme has clear control indicators, strong universality, and simple construction, which can effectively suppress penetrating shrinkage cracks, solve leakage problems, and improve project construction quality.

Description

An anti-cracking construction method for concrete of the main structure of an open-cut and cast-in-place tunnel technical field The invention belongs to the technical field of tunnel construction, specifically, relate to a kind of open-cut cast-in-place tunnel main structure concrete Soil crack resistance construction method. Background technique Although in the field of cut-and-cover cast-in-place tunnel structures, relevant personnel have accumulated many engineering practices, however, concrete The problem of cracking and leakage is still very prominent. Surveys and Research Results Sheets It is clear that most of the leakage is caused by the early shrinkage and cracking of concrete, except for a small part of leakage caused by improper joint treatment. Therefore, solving the early shrinkage and cracking of concrete is the key to controlling the leakage of open-cut and cast-in-place tunnel structures and ensuring the quality of engineering construction. Compare...

AI Technical Summary

Problems solved by technology

In addition, by summarizing the existing literature and engineering practice, it is found that reducing concrete constraints, reducing concrete temperature shrinkage, or simply combining multiple technological measures can effectively reduce the degree of shrinkage cracking of concrete, but the problem of concrete shrinkage cracking has not been completely solved.

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