Subway shield section boulder refining detecting method based on resistivity trans-hole CT (computed tomography)

Abstract

The invention discloses a subway shield section boulder refining detecting method based on resistivity trans-hole CT (computed tomography). The subway shield section boulder refining detecting method includes a scientific and reasonable drilling plane layout scheme of an unexcavated in front of a tunneling side; a detecting scheme of paving a resistivity trans-hole CT wiring net and combining two-dimensional general detecting survey with three-dimensional detailed detecting survey. Data acquisition acquires a novel combined observation mode, and more effective information related to abnormal boulder bodies can be acquired; by structuring a three-dimensional resistivity inversion target function and an inversion equation of a carrying distance weighting function, algorithms can be quickly analyzed and solved parallelly by a partial derivative matrix; a resistivity image result diagram of detection of the abnormal boulder body within a ranging range is formed, and size and spatial distribution and the like of the boulder body are deduced by being combined with geological analysis. Three-dimensional high-resolution accurate imaging of the abnormal boulder body can be realized, and power technical support is provided for safety and quick tunneling of construction tunnels by subway shield tunneling machines.

Description

technical field [0001] The present invention relates to a refined detection method for boulders in subway shield sections, in particular to a method based on resistivity cross-hole CT to detect boulder bodies or boulder groups in front of the tunnel excavation face under the conditions of subway shield tunneling machine construction tunnels A method for fine-grained detection. Background technique [0002] In recent years, my country's urban subway construction has ushered in a valuable period of opportunity and a climax of construction. In the process of subway construction, the construction method of shield boring machine has gradually become an important trend in the construction of subway projects in my country. Shield tunneling machine construction has the advantages of "fast tunneling speed, small construction disturbance, high-quality hole formation, high comprehensive economic and social benefits, and safe and civilized construction", but its adaptability to strata ...

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Problems solved by technology

[0006] ① Like other geophysical methods, the inversion and interpretation of the resistivity CT detection method has multiple solutions. In severe cases, the inversion results will be quite different from the actual situation, and it is difficult to accurately locate the boulder. Therefore, it is urgently needed Improve the multi-solution and inversion effect of trans-pore resistivity CT inversion problem;

[0007] ② The large amount of collected data is a major advantage of the resistivity trans-hole CT detection method, which can obtain more effective information about anomalies, but the inversion and interpretation of a large amount of data will be very time-consuming, and it is urgent to propose an improved method. Algorithms for inversion interpretation efficiency;

[0008] ③Unreasonable observation methods, inappropriate electrode spacing and drilling spacing will seriously affect the detection and identification capabilities of the resistivity CT method for boulder targets, resulting in large errors in boulder detection results and even failure to detect boulders Therefore, it is urgent to propose a scientific and reasonable observation method to improve the resolution and positioning accuracy of boulder detection;

[0010] ⑤ For geological anomalies close to a certain borehole, the corresponding shape in the inversion imaging results will be greatly distorted, and at the same time, it will affect the imaging quality of the adjacent area, and "redundant structures" or false anomalies will easily affect or mislead Geological Interpretation and Inference Work

[0011] 1. The inversion equation is highly sensitive to the abnormal body near the electrode, so that the abnormal body near the electrode is in a "dominant position" in the inversion process, resulting in a large distortion in the shape of the corresponding imaging result;

[0012] 2. The abnormal body is too close to the electrode, which will easily cause the local electric field near the electrode to be distorted, and the imaging result will be deviated.

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