为解决喷射混凝土工作环境差、能耗高以及施工中跑浆、漏浆等问题，提出钢波纹板结合模袋混凝土的新型支护方案。依托圆形竖井，采用倒挂井壁逆作施工法展开现场试验，分析灌注压力的变化规律及其影响。结果表明: 1）模袋混凝土可充填开挖面与钢波纹板之间的构造间隙及预留空间，与钢波纹板形成具有一定强度和刚度的组合结构，能够维持开挖面稳定、抵抗开挖面变形，施工工艺具有可行性； 2）根据现场监测结果可知，在混凝土灌注过程中，模袋内混凝土流动性良好，能充分填充模袋，注满后，灌注压力逐渐消散，且钢波纹板产生的环向应变很小，支护结构在工作状态下均匀受力； 3）试验选用的土工布均具有透气、透水、不透浆的特性，能有效解决喷射混凝土施工存在的跑浆、漏浆等问题，但材料特性和加工性能略有差异； 4）钢波纹板与模袋混凝土结合形成的新型支护结构，为隧道等地下工程支护技术提供了新思路，具有重要意义。
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 steelcorrugated 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 steelcorrugated 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 onsite 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 steelcorrugated 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.
