Anchor rod embedding device for true three-dimensional geomechanics model test, and operation method

Abstract

The invention discloses an anchor rod embedding device for a true three-dimensional geomechanics model test, and an operation method. The anchor rod embedding device comprises a base, a top cover, a connecting element, a protection cylinder and hoop rings, wherein the protection cylinder consists of two semicircular cylinders and is provided with anchor rod positioning holes. When the device is used, the protection cylinder is inserted into the trough of the base and is fixed with the base into a whole through the hoop rings. By use of the device, the technical problems in the true three-dimensional geomechanics model test that the system anchor rod is difficult in embedding, the position and the direction of the anchor rod is difficult in fixing and an embedding range is limited can be solved, and meanwhile, the device has the advantages of being simple in construction, convenient in disassembling, reliable and practical, and the operation method can be easily mastered and has a wideapplication prospect.

Description

technical field [0001] The invention relates to an underground engineering test device, in particular to a device and an operation method for pre-embedding anchor rods in model tests. Background technique [0002] The geomechanics model test method based on similarity theory has always been an important means to study the stability and safety control of surrounding rock in underground engineering, which has played a great role in promoting the development of underground engineering and provided a basis for engineering design and construction. Valuable test data. However, when performing bolt support in the true three-dimensional geomechanics model test, due to the limitations of the model size, test equipment and bolt embedding tools, the anchor bolts of the system are difficult to bury, and the direction and position of the anchor bolts are difficult to fix, which greatly hinders The development of true three-dimensional geomechanics model test bolting technology. [0003...

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Problems solved by technology

[0004] (1) "Journal of Civil Engineering" No. 9, 2011 introduced a method of pre-embedded anchor rods in model tests, which used a method of directly placing anchor rods at the position of the anchor rods when making the model body. The direction of the horizontal and vertical anchors can be kept unchanged, but it is difficult to fix the direction of the oblique anchors, and it is also difficult to ensure that the position of the anchors does not change during the subsequent filling compaction process.

[0005] (2) "Journal of Rock Mechanics and Engineering" No. 1, 2010 introduced a construction technique of grouting bolts in model tests, which used a slightly larger-diameter bolt pre-buried when making the model, and after excavation Pull it out to form the anchor hole, then insert the anchor rod and grout to block the hole. Due to the influence of the size of the anchor cavern in the model, this method cannot realize the anchor rod application at any part around the cave.

[0006] (3) "Journal of Rock Mechanics and Engineering", No. 12, 2014, proposed a method of pre-embedding anchor rods in true 3D model tests, which uses the method of trimming the compacted model body and setting up the positioning device to drill holes and embed the anchors Rod method, this method can only be used to construct the anchor rods in the upper part of the tunnel, and cannot construct the anchor rods in the lower part of the tunnel and the oblique anchor rods in the waist of the tunnel

[0007] (4) "Journal of Coal Science" No. 9, 2013 proposed a construction method of prestressed anchor rods in deep coal roadway geomechanical model tests, which uses manual drilling after roadway excavation, and then inserts them after injecting anchoring agent The method of anchoring and applying prestress, due to the influence of the model plus the size of the anchor cavern, this method cannot realize the anchoring of any part around the cavern

[0008] (5) The invention patent with the application number 201310102213.0 has developed a positioning device and positioning method for system anchor rod application in underground engineering model tests. Due to the influence of the model plus the size of the anchor cavern, the method of drilling holes with an angled pneumatic drill and embedding miniature anchors cannot realize the installation of anchors at any part around the hole, and at the same time, the positioning device can only roughly determine the anchors The embedding direction of the anchor hole will inevitably cause the deviation of the direction of the anchor hole when the angled air drill goes deep into the hole

[0009] (6) The invention patent with the application number 201510477771.4 has developed a physical simulation method that can locate and guide the pre-embedment of the bolt in the coal roadway. It adopts the method of embedding the positioning plate at the position of the anchor and fixing the anchor with bolts on the positioning plate. However, this method embeds the positioning plate into the model body, which will inevitably cause changes in the stress field at the location, and cannot simulate the real stress environment of the actual project. At the same time, this method cannot guarantee the subsequent filling and compaction of the model material. When the fixed anchor on the positioning plate does not deflect in direction

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