A method for determining the development range of surrounding rock weakening based on tunnel deformation

Abstract

The invention relates to a method for determining a weakening development range of a surrounding rock based on tunnel deformation, and the method comprises the following steps of step S1: collecting tunnel lining data Lj; step S2: calculating tunnel lining data Ls under different surrounding rock pressures by using a load structure method; step S3: establishing an objective function S related to the collected tunnel lining data Lj and the tunnel lining data Ls calculated by the load structure method, and recording the surrounding rock pressure P applied by the load structure method when the objective function S satisfies a set condition; step S4: calculating a surrounding rock loosening range hj according to the surrounding rock pressure P; step S5: calculating the surrounding rock loosening range hs under the design surrounding rock pressure; and step S6: obtaining the weakening development range hr of the surrounding rock according to the surrounding rock loosening range hj calculated by the surrounding rock pressure P and the surrounding rock loosening range hs under the design surrounding rock pressure. Compared with the prior art, the method provided by the invention has the advantages of speediness, nondestructive feature and high precision, is low in implementation cost, and can be widely applied to other similar underground projects such as pipe trunk trenches and pipejacking tunnels.

Description

technical field [0001] The invention relates to the technical field of tunnel safety, in particular to a method for determining the development range of surrounding rock weakening based on tunnel deformation. Background technique [0002] During the operation of the tunnel, due to the influence of high ground stress, geothermal, groundwater, etc., the mechanical properties of the surrounding rock are changed, the surrounding rock is weakened, the bearing capacity of the surrounding rock is reduced, and the original relatively stable state of the surrounding rock and the lining is broken. Threat to tunnel structure security. In order to ascertain the weakening range and degree of surrounding rock, the method of drilling samples and conducting indoor tests is usually adopted, but this method has the following defects: [0003] (1) Due to the limited number of drilled holes, it is usually difficult to accurately obtain the weakened range of the surrounding rock of the tunnel b...

AI Technical Summary

Problems solved by technology

[0003] (1) Due to the limited number of drilling holes, the weakening range of the surrounding rock in the undrilled part is usually estimated based on the drilling test results, and it is difficult to accurately obtain the weakening range of the tunnel surrounding rock

[0004] (2) The rock samples taken from the borehole are out of the original environment, and the test results cannot accurately reflect the mechanical properties of the rock mass

[0005] (3) The entire process of this method takes a long time, and it is easy to miss the best time for tunnel repair and reinforcement

[0006] (4) Drilling holes in the existing lining structure is also a kind of damage to the lining itself, which reduces the bearing capacity of the lining structure

Images