Technical Research on Covered-Cut Method of Truncated Vertical Wall Frame Structure

摘要

In the stratum of the Quaternary Period, most large underground works executed by traditional covered-cut method are of curved wall continuous arched sections. With this technique, large underground works can be constructed into truncated vertical wall rectangular sections. As a result, the form of structure, which would be built only by using open-cut method, can now be executed by covered-cut method. Therefore, it is necessary to resolve three technical problems: 1. Research and determine execution method, resolve the problem of landslide of earth body in the execution process, and control ground subsidence; 2. Rational conversion between support form and structural stress system; 3. Structural stress analysis of execution and use phase. By using this technique, we have already constructed several projects in Beijing, including 6 crossing underground street passageways 11.7m (width) * 4.35m (height) (Outskirt-Outskirt, the same below); an underground square hall 29.0m (length) * 28.0m (width) * 6.65m (height), a subway double line interzone tunnel 286m (length) * 10.8m (width) * 6.05m (height) etc. During their execution, stratum's stabilization has been ensured with a high rate of space utilization as well as a notable economic benefit. Patent application has already been made for this execution method, its patent no. being 95105999.8-5.