Structure and method for constructing multilayer heterogeneous gob-side entry retaining filling wall

Abstract

A structure and method for constructing a multilayer heterogeneous gob-side entry retaining filling wall optimizes structural patterns and materials of the gob-side entry retaining filling wall, divides a wall body into an upper layer, a middle layer and a lower layer or a plurality of layers, forms a hard-soft-hard structure from top to bottom. The height of the middle layer and the upper layer is generally 5%-25% of the mining height, the upper layer of the wall body is generally filling materials, and the upper layer of the wall body is mainly fracture rotation and subside enabling an old top to keep complete, and impulse load of the top plate is transmitted to the middle layer of the wall body. The middle filling material can be materials such as polyester chemical materials and polypropylene fiber concrete with toughness and is mainly used for buffering and absorbing deformation and impact energy caused by fracture rotation of the old top. The lower layer is a bearing layer and is generally materials such as reinforced concrete with big compressive strength, and the lower layer is mainly used for providing certain supporting force for pressure of the old top. A strengthening reinforcing steel bar is distributed at the layering connection position, and damage of carrying capacity of the wall body caused by relative sliding between layers is avoided.

Description

technical field [0001] The invention relates to a structure and a method for constructing a multi-layered heterogeneous gobside entry filling wall, and is especially suitable for a continuous mining method without coal pillars when the coal mining face uses paste masonry to fill the wall. Background technique [0002] Gobside retaining technology has been used in my country since the 1950s. It is a form of coal pillar-free roadway protection. It is beneficial to the rational development of coal resources, improves the recovery rate of coal resources, and reduces the amount of roadway excavation. The advantages of improving the tense situation of mine excavation replacement and improving roadway maintenance have been widely valued. [0003] At present, when my country's coal mines apply gob-side entry retaining technology, most of them must set up roadside support, and the most widely used roadside support forms mainly include wooden piles and single pillars. With the continu...

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Problems solved by technology

[0005] At present, many scholars in China have proposed to add some flame-retardant wood blocks or soft joints on the upper surface of the filling wall, which can solve the problem of the wall and roof joint, but the wood blocks are easy to cause damage. Coal spontaneously ignites in the goaf, and the soft medium roof can also solve the rotary pressure of the roof and buffer the impact load, and the width of the soft medium is only half of the wall width. Although the filling material is saved to a certain extent, it is difficult to guarantee longitudinal stability of the wall

It is also proposed to change the yielding effect of the upper wall by unequal and strong roofing. The main method is to arrange the prepared gangue bags tightly on the upper layer after the lower filling wall is solidified. This method makes full use of the mined gangue. "Turning waste into use" has greatly improved the situation of the butt joint roof, but this method is difficult to ensure a good and dense contact between the upper gangue bag and the lower filling wall, and is prone to instability

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