Determination method of tunnel surrounding rock prestressing force reinforcing anchor rod length and radial prestressing force values

Abstract

The invention discloses a determination method of tunnel surrounding rock prestressing force reinforcing anchor rod length and radial prestressing force values. According to the surrounding rock elastic-plastic theory and the plastic zone distribution regulation, and, on the basis that a tunnel plastic ring radius R and a surrounding rock pressure force are comprehensively determined, the minimum length value and a radial minimum prestressing force value of a tunnel surrounding rock reinforcing anchor rod are determined. The determination method advantageous in that, according to the surrounding rock elastic-plastic theory and the plastic zone distribution regulation, and, on the basis that the tunnel plastic ring radius R and the surrounding rock pressure force are comprehensively determined, the minimum length value and the radial minimum prestressing force value of the tunnel surrounding rock reinforcing anchor rod are determined, the calculation process is relative clear and concise, and a measured result is high in accuracy and accurate, has a small error compared with the actual and can guide the practice well.

Description

technical field [0001] The invention relates to the fields of stress measurement of tunnel surrounding rock, stability evaluation of tunnel surrounding rock and lining support reinforcement design method, in particular to a method for measuring the length of a tunnel surrounding rock prestressed reinforcement bolt and the radial prestress value. Background technique [0002] In recent years, with the construction of more and more tunnel projects, my country has made remarkable achievements in the fields of transportation, water conservancy and hydropower, and municipal infrastructure. Especially in the past ten years, it has achieved rapid development. At the same time, underground The level of engineering design and construction technology has also been greatly improved. [0003] At present, in order to maintain the use clearance of the tunnel section, withstand various loads that may occur, and ensure the stability and safety of the surrounding rock of the tunnel, it is oft...

AI Technical Summary

Problems solved by technology

Although the above prediction method has played an important role in the general design of anchor shotcrete support, by analyzing the establishment process of the above design method, it can be found that the above method has the following deficiencies: the engineering analogy method and the information design method are mainly based on practical experience Or the actual measured data is the design basis, but it is often affected by objective practical conditions, measurement accuracy, measurement methods and measurement tools, resulting in large errors in its actual application, and the lack of theoretical calculation basis makes the above method It cannot be really effectively used in engineering construction; although the development of theoretical calculation methods has been mature, there are not many such calculation methods used, mainly because the surrounding rock geological conditions are complex and changeable, and its mechanical models and rock mass mechanical parameters It is not easy to accurately test and determine, so it is generally only used as a calculation method in the design, and it is mutually checked with other design methods

[0005] From the above analysis, it can be concluded that there is no complete theoretical calculation system for the design of anchor-sprayed support for underground chambers at home and abroad, and it is difficult to apply the existing theoretical calculation methods to the design of support structures effectively and accurately. For this reason, the present invention determines the minimum length of the tunnel surrounding rock reinforcement bolt and the minimum radial prestress value on the basis of comprehensively determining the radius R of the tunnel plastic circle and the surrounding rock pressure according to the elastic-plastic theory of the surrounding rock and the distribution law of the plastic zone.

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