关键词: 地下工程, 圆形竖井, 钢波纹板, 模袋混凝土, 倒挂井壁逆作法, 支护结构, 工艺试验

Abstract:  Shotcrete construction has some drawbacks, such as poor working environment, high energy consumption, slurry running, and slurry leakage. Thus, a novel support scheme by integrating a steelcorrugated plate combined with a mold bag concrete is proposed. A field experiment is conducted on a circular shaft using the inverted hanging shaft wall reverse construction method, and the change law of perfusion pressure and its influence are analyzed. The following are the results obtained in this study. (1) The mold bag concrete can fill the structural gap and reserved space between the excavation surface and steelcorrugated plate to form a composite structure with certain strength and stiffness, which can maintain the stability and resist the deformation of the excavation face. (2) The onsite monitoring results show that in the process of concrete pouring, the concrete in the mold bag has good fluidity and can completely fill the mold bag. Then, the pouring pressure dissipates gradually, and the circumferential strain produced by the steelcorrugated plate is small. The supporting structure is subjected to uniform force under such working conditions. (3) The geotextiles selected in the test have the characteristics of air and water permeability, which can effectively solve the problems of slurry running and leakage during shotcrete construction. (4) The proposed supporting structure provides innovative ideas for tunneling and similar underground engineering support technology, which is of great significance.

Key words: underground engineering, circular shaft, corrugated steel plate, mold bag concrete, inverted hanging shaft wall reverse, supporting structure, process test