CN202578781U - Layered load-bearing filling structure beside hard roof gob-side entry retaining - Google Patents

Abstract

The utility model discloses a layered load-bearing filling structure beside a hard roof gob-side entry retaining. The layered load-bearing filling structure is characterized by comprising an upper layer of filling bodies and a lower layer of filling bodies, and the upper layer of the filling bodies and the lower layer of the filling bodies are different in strength. The upper layer of the filling bodies is formed by stacking of yielding gangue bags with the width of 0.4-0.6 meter and the length of 1.2-1.5 meters. The lower layer of the filling bodies is a high-strength paste filling wall. The layered load-bearing filling structure can well adapt to movement rules of hard roof rock strata, and stability of the gob-side entry retaining is guaranteed.

Description

Layered load-bearing filling structure next to gob-side entry retention with hard roof

technical field

The utility model relates to a filling technology applied in underground coal mines, in particular to a filling structure and a construction method beside a gob-side roadway under the condition of a hard roof.

Background technique

Backfilling along the gob-side roadway is a major reform of coal mining technology. This technology can not only improve the recovery rate of coal resources, extend the service life of the mine, reduce the amount of roadway excavation, alleviate the contradiction of mining replacement, and cancel the island working face. It is also the most effective way for mines to reform their coal mining methods.

At present, the commonly used filling methods for gob-side entry retention at home and abroad mainly include cement-based paste filling, gangue belt filling, high-water quick-setting material filling and so on. Due to the gob-side entry retention under the condition of a hard roof, the working face basically has a long time to hang from the top and a large distance from the top, the defects of the above three filling methods are: the filling body next to the road will bear a large roof pressure, and for cement The base paste filling body has low initial strength and poor shrinkability, and cannot well adapt to the movement of hard rock formations; the filling workload of the gangue belt is large, and the support resistance provided by the gangue belt is small, and the support effect is poor; The cost of high-water quick-setting materials is high, the support strength is low, and it is not suitable for the high-pressure mutation of the gob-side roadway. During the secondary mining of the working face, the filling body is easily deformed and damaged, resulting in serious air leakage in the gob. And the maintenance of the roadway has brought great difficulties.

Utility model content

In order to overcome the defects of complicated construction, high cost, and uncertain yield pressure of the existing gob-side entry filling structure under the condition of a hard roof, the utility model provides a new type of filling technology, which is a combined filling structure of unequal strength. This unequal-strength combined filling structure has the function of yielding pressure, and its underlying filling body can provide higher support strength.

In order to achieve the above tasks, the layered load-bearing filling structure of the present invention is composed of upper and lower layers of unequal-strength filling bodies. piled up; the lower filling body is a high-strength paste filling wall.

Compared with other filling structures for gob-side retaining, the utility model has the following advantages:

1. Use unequal strength for combined filling, taking into account the advantages of gangue belt filling and paste filling. For the hard roof with long suspension time and large suspension distance, the structure can provide better yielding effect in the early stage and relieve pressure. The roof sinks so that the filling body will not be crushed under the high roof pressure, and the overall structure in the later stage provides high support resistance to ensure the stability of the gob-side entry retention.

2. The upper filling body of the utility model has the function of yielding pressure, and the height of the yielding pressure can be greater than the sinking height of the roof within a reasonable range, and the hard roof can completely withstand a small impact without warning, so during construction , in order to ensure the success of the roadway retention, before the lower filling body condenses, it is only necessary to use the single hydraulic prop beside the roadway as the lagging support and the wooden prop in the goaf for the initial support, without using the costly bolt support, and the stability is stable. It has good performance and reduces the construction cost; when the roadway is used up, all the single hydraulic props in the roadway can be recycled, which further reduces the cost of the roadway.

In a word, under the premise of reducing the cost of the filling body and the construction cost, the filling body of the utility model realizes the purpose that the amount of pressure can completely withstand the sinking amount of the roof. Significant advances in technical problems that people want to solve but do not.

Description of drawings

Fig. 1 is the perspective view of the utility model structure.

Fig. 2 is the specific construction schematic diagram of the utility model structure.

The numbers in the figure represent respectively: 1-lower filling body, 2-upper filling body, 3-spraying machine, 4-spraying pipeline, 5-advance support, 6-single hydraulic prop of working face, 7-working face, 8-filling template, 9-retaining roadway, 10-unequal strength combined filling body, 11-wooden pillar, 12-goaf, 13-temporary support, 14-lag support.

Detailed ways

Fig. 1 is a schematic structural view of the utility model, as can be seen from the figure, it is composed of two kinds of unequal-strength filling bodies, the upper filling body 2 and the lower filling body 1, and the upper filling body is made with a width of 0.4- 0.6 meters and 1.2-1.5 meters long are piled up by pressing gangue bags; the lower filling body is a high-strength paste filling wall.

List an embodiment below in detail and can implement the mode of the utility model structure.

Taking the filling height of the upper filling body as h ₁ , the filling material of the pressure gangue bag in the upper filling body is composed of a mixture of water, cement and crushed gangue with a mass ratio of 1:1.7:5, and the initial setting time of the mixture is required to be 30- 40min, final setting time 1.5-2.5h, after final setting, the compressive strength of the gangue bag reaches 2-3MPa; after 28 days, the compressive strength of the gangue bag reaches 10-20MPa;

The filling height of the paste filling wall from the lower filling body is _h2 , and the paste filling wall is composed of water, cement, waste gypsum, blast furnace slag, waste lime, A mixture of fly ash and gangue powder is formed; the compressive strength of the paste filling wall material is required to reach 5-10MPa in 1 day, 10-20MPa in 3 days, 20-28MPa in 7 days, and 30-35Mpa in 28 days;

The above filling heights _h1 and _h2 are determined by the following method:

Step 1: Calculate the actual settlement value S _A of the rock beam according to the mining height value and the thickness of the direct roof

S _A ＝ hm _z (K _A -1)

In the formula:

h-mining height;

m _z - immediate roof thickness;

K _A - the disintegration coefficient of the rock formation at the lower part of the rock beam touching gangue, which is taken as 1.25-1.35;

Step 2: Calculate the filling height h ₁ of the upper filling body according to the actual settlement value S _A of the rock beam

h ₁ =α ₀ S _A /α

In the formula:

α- yield coefficient of upper filling body, take 0.2;

α ₀ - yield safety factor, take 1.5;

Step 3: Calculate the filling height h ₂ of the lower filling body according to the mining height h and the height h ₁ of the upper filling body

h ₂ =hh ₁ .

The construction method of structure of the present utility model is described in detail below with reference to accompanying drawing 2.

Step 1: After the excavation of the underground roadway, carry out anchor, cable, net, belt support and 6 supports of single hydraulic props on the working face, and arrange the working face at the same time. The goaf 12 is formed after the coal is coaled.

Step 2: Use a single hydraulic prop in the retaining entry 9 as the advance support 5 plus a hinged top beam support, and then use wooden pillars 11 for support and reinforcement within the filling width of the retaining entry side. With the advancement of the working face, the advance A single hydraulic prop is added to the support 5, and it is strengthened into a lag support 14. The lag support 14 and the wooden pillar 11 jointly bear the initial pressure of the roof before the lower filling body condenses.

Step 3: At the same time, the ground starts to prepare materials, prepare filling materials such as water, cement, gangue, and fly ash, and transport them to the retention lane.

Step 4: Set up temporary support 13 and filling formwork 8 behind the working face, the filling height is h ₂ , and the filling material of the lower filling body is injected into the filling formwork 8 by the shotcrete machine 3 through the spraying pipe 4 for paste Body filling, as the lower filling body 1 in the structure shown in Fig. 1 .

Step 5: After the paste filling body of the lower filling body 1 is solidified, fill the pasty filling body with gangue bags and arrange them closely, and stack them on the top plate to form the upper filling body 2 of the filling structure in Figure 1. In Fig. 1 of this embodiment, only one layer of gangue bags is drawn. In actual engineering, the number of layers of gangue bags to be piled up depends on the compacted thickness of the materials in the gangue bag after final setting and the filling height of the gangue bag.

Step 6: After the gangue bag of the upper filling body 2 is solidified for 2-3 days, remove the temporary support 13, and at the same time recover the lag support 14 on both sides of the roadside and the upper filling body outside the range of 200 meters behind the working face. 2 and the lower filling body 1 form a combined filling body 10 of different strengths shown in FIG. 2 .

Step 7: At the same time, repeat the above steps 2 to 6 as the working face advances.

Claims (1)

1. A layered load-bearing filling structure next to a gob-side retaining entry with a hard roof, which is characterized in that it is composed of two layers of unequal-strength filling bodies, and the upper filling body is 0.4-0.6 meters wide and long. 1.2-1.5 meters of gangue bags are piled up; the lower filling body is a high-strength paste filling wall.

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