WO2021103192A1

WO2021103192A1 - Supporting structure for preventing roadway surrounding rock from transferring heat

Info

Publication number: WO2021103192A1
Application number: PCT/CN2019/125573
Authority: WO
Inventors: 郭忠平; 何程乾; 张延旭; 张福玉; 冷超
Original assignee: 山东科技大学
Priority date: 2019-11-29
Filing date: 2019-12-16
Publication date: 2021-06-03
Also published as: CN211081909U

Abstract

Disclosed is a supporting structure for preventing roadway surrounding rock from transferring heat, relating to the technical field of roadway supporting. The supporting structure comprises supporting anchor rods (1), an anchoring and shotcreting concrete layer (2), a rigid polyurethane foam layer (3) and a gridding cloth mortar layer (4), wherein the supporting anchor rods (1) are arranged on a roadway, the anchoring and shotcreting concrete layer (2) is tightly attached to roadway surrounding rock, the rigid polyurethane foam layer (3) is arranged on the anchoring and shotcreting concrete layer (2) in a pressing manner, the gridding cloth mortar layer (4) is arranged on the rigid polyurethane foam layer (3), the section shape of the anchoring and shotcreting concrete layer (2) is the same as that of the roadway, the anchoring and shotcreting concrete layer (2) is of a solid structure and is smooth in terms of surface, the rigid polyurethane foam layer (3) evenly and smoothly covers the anchoring and shotcreting concrete layer (2), the gridding cloth mortar layer (4) comprises gridding cloth (9) and mortar, the gridding cloth (9) is hung on the rigid polyurethane foam layer (3) via an exposed end of the anchor rod, and the mortar is wrapped around the gridding cloth (9) and cured on the rigid polyurethane foam layer (3). The supporting structure can control deformation of roadway surrounding rock and also prevent heat of the roadway surrounding rock from being transmitted into the roadway.

Description

Supporting structure for preventing heat transfer in surrounding rock of roadway

Technical field

The utility model relates to the technical field of roadway support, in particular to a support structure that prevents heat transfer from the surrounding rock of the roadway.

Background technique

With the rapid development of the economy, the demand for energy has increased greatly, and coal resources have been exploited in a large amount; with the continuous increase in the depth of mine mining, the problem of mine thermal damage has become more and more serious. The management of mine thermal damage affects the sustainable development of many mining enterprises . At present, the treatment of mine thermal hazards is mainly based on passive cooling methods such as increasing ventilation, cooling and ice making. The cooling of the mine insulation material is an active cooling method by adding low thermal conductivity materials around the roadway to prevent the heat from the surrounding rock of the roadway from being released to the inside of the roadway. The research and application of thermal insulation materials in construction technology and aerospace industry have been very extensive. New thermal insulation materials are used in mines affected by heat damage. By adding thermal insulation materials on the wall of the roadway, the deep heat source of the roadway can be isolated and the surrounding rock can be prevented from radiating heat. Achieve active cooling effect and save cooling cost.

However, due to the dangers in mine mining and the inconvenience of construction, it is necessary to set up a reasonable roadway support structure. By building a layer of thermal insulation material to prevent the heat transfer of the surrounding rock of the roadway, and to avoid affecting the stability of the support structure of the surrounding rock of the roadway. The existing supporting structure needs to be further improved.

Summary of the invention

technical problem

The solution to the problem

Technical solutions

In order to control the deformation of the surrounding rock of the roadway and prevent the heat from the surrounding rock of the roadway from being transferred into the roadway, the utility model provides a supporting structure for preventing the heat transfer of the surrounding rock of the roadway. The specific technical scheme is as follows.

A supporting structure for preventing heat transfer to the surrounding rock of a roadway, comprising supporting bolts and a shotcrete concrete layer. The supporting bolts are arranged in the roadway, and the bolting and shotcreting concrete layer is arranged close to the surrounding rock of the roadway; it is characterized in that it also includes hard A polyurethane foam layer and a grid cloth mortar layer, the hard polyurethane foam layer is fixed on the anchor shotcrete layer, and the grid cloth mortar layer is arranged on the hard polyurethane foam layer; the cross-sectional shape and the roadway of the anchor shot concrete layer The cross-section shape is the same, the anchor shotcrete layer is a solid structure and the surface is flat, the rigid polyurethane foam layer is evenly and evenly covered on the anchor shotcrete layer, the grid cloth mortar layer includes grid cloth and mortar, and the grid cloth is exposed through the anchor rod The ends are hung on the rigid polyurethane foam layer, and the mortar wraps the grid cloth and is consolidated on the rigid polyurethane foam layer.

Preferably, the thickness of the anchor shotcrete layer is less than 20 mm, the thickness of the rigid polyurethane foam layer is greater than 30 mm, and the thickness of the grid cloth mortar layer is 1.5-3 mm.

Preferably, the cross section of the roadway is rectangular, trapezoidal, semicircular arch, arc arch, oval or circular.

Preferably, barbs are provided on the grid cloth.

The beneficial effects of the invention

Beneficial effect

The beneficial effect of the utility model is that the stability of the overall support structure of the roadway is ensured by the reasonable arrangement of the supporting bolts and the bolt shotcrete layer, the rigid polyurethane foam layer is arranged to prevent the heat transfer of the surrounding rock of the roadway, and the hard High-quality polyurethane foam has the advantages of convenient construction and good heat insulation performance; and considering the deformation of the surrounding rock of the roadway, the installation of a rigid polyurethane foam layer can ensure the shear resistance and compression performance of the supporting structure; the installation of a grid cloth mortar layer can protect The rigid polyurethane foam layer improves the overall thermal insulation and stability of the structure.

Brief description of the drawings

Description of the drawings

Figure 1 is a schematic diagram of the supporting structure to prevent heat transfer to the surrounding rock of the roadway;

Figure 2 is a schematic diagram of the grid cloth structure;

Figure 3 is a schematic diagram of the barb structure;

Figure 4 is a schematic diagram of the supporting process of the insulated roadway;

In the picture: 1- supporting anchor rod; 2- anchor shotcrete layer; 3- rigid polyurethane foam layer; 4- mesh cloth mortar layer; 5- pointed end; 6-connecting rod; 7- fin plate; 8- Barb; 9-grid.

Invention embodiment

Embodiments of the present invention

With reference to Figures 1 to 4, the specific implementation of a supporting structure for preventing heat transfer from surrounding rocks of a roadway provided by the present invention is as follows.

Example 1

A supporting structure to prevent heat transfer to the surrounding rock of a roadway. The specific structure includes a supporting bolt and a shotcrete concrete layer. A supporting bolt 1 is set on the roadway, and a shotcrete bolt 2 is set close to the surrounding rock of the roadway. The rigid polyurethane foam layer 3 and the grid cloth mortar layer 4, the rigid polyurethane foam layer 3 is fixed on the anchor shotcrete layer 2, and the grid cloth mortar layer 4 is arranged on the rigid polyurethane foam layer 3. Among them, the thickness of the anchor shotcrete layer 2 is less than 20mm, the thickness of the rigid polyurethane foam layer 3 is greater than 30mm, and the thickness of the grid cloth mortar layer 4 is 1.5-3mm.

The cross-sectional shape of the shotcrete layer 2 is the same as that of the roadway, and the shotcrete layer 2 has a solid structure and has a flat surface. The anchor shotcrete layer 2 includes a first concrete layer and a second concrete layer. The first concrete layer is formed by spraying concrete in the roadway. The thickness of the first concrete layer is less than 8cm. After the first concrete layer is solidified, the second concrete layer is sprayed. The thickness of the second concrete layer is greater than 10 cm. The rigid polyurethane foam layer is evenly and evenly covered on the anchor shotcrete layer. The grid cloth mortar layer includes grid cloth 9 and mortar. The grid cloth 9 is hung on the rigid polyurethane foam layer through the exposed end of the anchor rod. The wrapping grid cloth is fixed on the rigid polyurethane foam layer.

In addition, the roadway section can be rectangular, trapezoidal, semi-circular arch, arc arch, ellipse or circle and other irregular shapes. Barbs are provided on the grid cloth, so that it is convenient for the grid cloth to be hung in the place where the anchor distance is large, and the grid cloth mortar layer and the rigid polyurethane foam layer are closely attached to facilitate the spraying of the mortar; the structure of the barb 8 Specifically, a pointed head 5, a connecting rod 6 and a fin plate 7 are provided, 3-4 fin plates 7 are arranged in a cone shape around the pointed head 5, and the rear end of the barb 8 is sleeved and fixed on the mesh cloth 9 in a ring shape. The barb is made of plastic material to reduce costs.

The specific construction of the support structure is to spray concrete on the roadway wall for the first time to level the roadway wall; then drill holes and install bolts for support, using high-strength bolts, nuts and pallets. Control the deformation of the surrounding rock and maintain the stability of the rock formation. After the concrete has hardened to a certain extent, spray rigid polyurethane foam using on-site spraying. Use a high-pressure spray gun to spray the mixture on the wall surface, try to ensure that the thickness is uniform, and there should be no thickness less than 30mm. Use a spatula to remove the excessively thick areas, and use rigid polyurethane foam to make up the excessively thin areas. Affected by the environment, the wind power during construction should not be greater than level 3, and the relative humidity of the air should be less than 70%, which can avoid the problems of environmental pollution caused by foam splashing during spraying and high material waste rate. After the rigid polyurethane foam is cooled and cured, it is hung with a grid cloth to spray polymer cement mortar to improve the durability of the material.

Reasonable setting of supporting bolts and shotcrete concrete layer ensures the stability of the overall support structure of the roadway. The rigid polyurethane foam layer is set to prevent the heat transfer of the surrounding rock of the roadway. The rigid polyurethane foam is used for convenient construction and thermal insulation performance. Good advantages. And considering the deformation of the surrounding rock of the roadway, the setting of a rigid polyurethane foam layer can ensure the shear resistance and compression performance of the supporting structure; the setting of a grid cloth mortar layer can protect the rigid polyurethane foam layer and improve the overall thermal insulation of the structure And stability.

Example 2

In order to further illustrate the beneficial effects of the roadway support structure, the construction method of the structure will be described.

The insulated roadway includes the supporting bolt 1, the shotcrete concrete layer 2, the hard polyurethane foam layer 3 and the grid cloth mortar layer 4. The anchor shotcrete layer 2 is set close to the surrounding rock of the roadway, and the 3 layers of hard polyurethane foam are fixed in On the anchor shotcrete layer 2, the grid cloth mortar layer 4 is arranged on the rigid polyurethane foam layer 3. The concrete structure includes supporting bolts and shotcrete concrete layer. Support bolts 1 are set in the roadway, and shotcrete concrete layer 2 is set close to the surrounding rock of the roadway. It also includes a rigid polyurethane foam layer 3 and a grid cloth mortar layer 4. The rigid polyurethane foam layer 3 is fixed on the anchor shotcrete layer, and the grid cloth mortar layer 4 is arranged on the rigid polyurethane foam layer 3. Among them, the thickness of the anchor shotcrete layer 2 is less than 20mm, the thickness of the rigid polyurethane foam layer 3 is greater than 30mm, and the thickness of the grid cloth mortar layer 4 is 1.5-3mm.

The cross-sectional shape of the shotcrete layer 2 is the same as that of the roadway, and the shotcrete layer 2 has a solid structure and has a flat surface. The anchor shotcrete layer includes a first concrete layer and a second concrete layer. The first concrete layer is formed by spraying concrete in the roadway. The thickness of the first concrete layer is less than 8cm. After the first concrete layer is solidified, the second concrete layer is sprayed. The thickness of the second concrete layer is greater than 10cm. The rigid polyurethane foam layer 3 is evenly and evenly covered on the anchor shotcrete layer. The grid cloth mortar layer 4 includes grid cloth and mortar. The grid cloth is hung on the rigid polyurethane foam layer through the exposed end of the anchor rod. The wrapping mesh cloth is consolidated on the rigid polyurethane foam layer, and the mesh cloth adopts medium alkali or alkali-free glass fiber mesh cloth. In addition, the roadway section can be rectangular, trapezoidal, semi-circular arch, arc arch, ellipse or circle and other irregular shapes. Barbs are provided on the grid cloth, so that it is convenient to hang the grid cloth in the place where the anchor distance is large, and to ensure that the grid cloth mortar layer and the rigid polyurethane foam layer are close together to facilitate the spraying of the mortar; the structure of the barb is specific It is provided with a pointed head, a connecting rod and a fin plate, and 3-4 fin plates are arranged in a cone shape around the pointed head. The rear end of the barb is sleeved and fixed on the intersection of the grid cloth in a ring shape. Plastic material production reduces costs.

A method for supporting an insulated roadway is disclosed, and the supporting steps include:

Step 1. Spray concrete on the wall of the newly excavated roadway to level the wall of the roadway to form the first concrete layer; the thickness of the first concrete layer is less than 8cm. For the newly excavated and formed high-temperature roadway, carry out bolt and shotcrete support and level the roadway wall to control the deformation of the surrounding rock and maintain the stability of the rock formation.

Step 2. Construct bolt drilling on the flat roadway wall, install bolts, pallets and nuts, support the roadway, and control the deformation of the surrounding rock of the roadway. Among them, the bolt parameters are diameter Φ=25mm, each length is 2m, the spacing is 800mm, and the row spacing is 800mm. Anchor cables can also be set to strengthen the support of the roadway.

Step 3. Spray the concrete again to form an anchor spray concrete layer. After the concrete is hardened, spray hard polyurethane foam to form a hard polyurethane foam layer. Wherein, the thickness of the second concrete layer formed by spraying concrete again is greater than 10cm, and the thickness of the first concrete layer and the second concrete layer combined to form the anchor shotcrete layer is less than or equal to 20cm. The spraying of rigid polyurethane foam uses the on-site spraying method. Specifically, the rigid polyurethane foam is sprayed on the surface of the wall with a high-pressure spray gun, and the spraying is repeated to ensure uniform thickness. The wind power in the tunnel during construction is less than 3, and the relative humidity of the air is less than 70%. , It can avoid the problems of easy splashing of foam during spraying to cause environmental pollution and high material waste rate; the thickness of the rigid polyurethane foam layer is greater than 30mm.

Step 4. Check whether the rigid polyurethane foam is evenly sprayed. The thickness is greater than or equal to 30cm. The locations where the thickness is greater than 33cm are removed with a shovel. The locations that are too thin and less than 27cm are filled with rigid polyurethane foam. The preparation method of rigid polyurethane foam is to use polyether resin and isocyanic acid as the main raw materials to add into the material mixer at a ratio of 1:1 and mix, and use the carbon dioxide generated in the reaction as the blowing agent. After a period of time, The rigid polyurethane foam can be obtained. It can be sprayed directly on the building interface, and after about 30 minutes of reaction cooling and finalization, it completely adheres to the building interface.

Step 5. After the rigid polyurethane foam is cooled and cured, a grid cloth is hung, and then polymer cement mortar is sprayed on the grid cloth, and the cement mortar is solidified to form a grid cloth mortar layer. The thickness of the grid cloth mortar layer is 1.5-3mm. The main components of polymer cement mortar are cement, aggregates and organic polymers that can disperse water. After these proportions are added to the water, they can be used after stirring. Specifically, after the concrete is hardened to a certain extent, rigid polyurethane foam is sprayed to form an insulating layer after foaming to prevent the high temperature from spreading to the roadway; after the rigid polyurethane foam is cooled and cured, the polymer cement mortar is sprayed on a grid cloth, and finally a barrier is formed. Thermal support system.

The construction process of the insulated roadway support method is convenient and efficient, and cost-saving. The first concrete layer is constructed first to ensure the surface of the surrounding rock of the roadway is smooth, and it is also convenient to set the anchor bolts and cables, which ensures the accurate setting of the bolts and the flatness of the pallets. , Improve the supporting effect; the second concrete spray layer re-spraying ensures the effectiveness of the anchor spray concrete layer, and the sequential spraying of the first spray layer and the second spray layer can improve the construction efficiency, and the anchor spray concrete layer can harden faster ; The construction of the rigid polyurethane foam layer is more convenient, and the price is low, energy saving and environmental protection. The rigid polyurethane foam will not break and damage its thermal insulation performance, and has excellent impact resistance; it is more convenient to hang the grid cloth and the grid cloth mortar Layer layout.

Among them, the selection of rigid polyurethane foam is obtained through comparison of similar structures. In order to select suitable thermal insulation materials to form a thermal insulation structure and prevent thermal damage from the periphery of the shaft, the comparison of rigid polyurethane foam, polystyrene material and polystyrene The composition structure of styrene EPS is combined with the heat transfer characteristics of tunnel support in deep mines. For example, as shown in Table 1, rigid polyurethane foam with a thickness of 25mm can achieve 50% thermal insulation and low cost, making it an ideal thermal insulation material. Moreover, the construction of the rigid polyurethane foam layer is more convenient, and the price is low, energy saving and environmental protection. The rigid polyurethane foam will not break and damage its thermal insulation performance, and has excellent impact resistance; it is more convenient to hang the grid cloth and the grid cloth mortar Layer layout.

Table 1

Rigid polyurethane foam is one of the materials with the lowest thermal conductivity among all thermal insulation materials. The thermal insulation effect of 50mm thick rigid polyurethane foam is equivalent to 90mm thick mineral wool, 100mm thick cork, 130mm thick fiberboard, and 280mm thick. Wood board or 760mm thick concrete, which allows it to effectively preserve heat and maintain a low temperature environment. Rigid polyurethane foam has high compressive strength and shear strength, and can effectively bond with various widely used surface materials. These materials can increase the inherent strength of rigid polyurethane foam and make it usable as a semi-structural sheet. Rigid polyurethane foam will not rupture and damage its thermal insulation performance, and has excellent impact resistance. The thermal insulation material rigid polyurethane foam can also be used under extreme conditions of -70℃-+130℃, which makes the supporting system have the advantages of anti-aging and moisture resistance, simple construction and mature construction technology as support. Rigid polyurethane foam is green and safe. Rigid polyurethane foam does not contain toxic chemical raw materials, is safe and has no toxic side effects to the human body, and the raw materials can be recycled, low price, energy saving and environmental protection.

In this method, the supporting bolts and the shotcrete concrete layer are set reasonably to ensure the stability of the overall support structure of the roadway. The rigid polyurethane foam layer is set to prevent the heat transfer of the surrounding rock of the roadway. The rigid polyurethane foam is used for convenient construction and isolation. Advantages of good thermal performance. And considering the deformation of the surrounding rock of the roadway, the setting of a rigid polyurethane foam layer can ensure the shear resistance and compression performance of the supporting structure; the setting of a grid cloth mortar layer can protect the rigid polyurethane foam layer and improve the overall thermal insulation of the structure And stability.

Of course, the above description is not a limitation of the present utility model, and the present utility model is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the utility model are also It should belong to the protection scope of the utility model.

Claims

A supporting structure for preventing heat transfer to the surrounding rock of a roadway, comprising supporting bolts and a shotcrete concrete layer. The supporting bolts are arranged in the roadway, and the bolting and shotcreting concrete layer is arranged close to the surrounding rock of the roadway; it is characterized in that it also includes hard A polyurethane foam layer and a grid cloth mortar layer, the hard polyurethane foam layer is fixed on the anchor shotcrete layer, and the grid cloth mortar layer is arranged on the hard polyurethane foam layer; the cross-sectional shape and the roadway of the anchor shot concrete layer The cross-section shape is the same, the anchor shotcrete layer is a solid structure and the surface is flat, the rigid polyurethane foam layer is evenly and evenly covered on the anchor shotcrete layer, the grid cloth mortar layer includes grid cloth and mortar, and the grid cloth is exposed through the anchor rod The ends are hung on the rigid polyurethane foam layer, and the mortar wraps the grid cloth and is consolidated on the rigid polyurethane foam layer.
The supporting structure for preventing heat transfer to the surrounding rock of a roadway according to claim 1, wherein the thickness of the bolted shotcrete layer is less than 20mm, the thickness of the rigid polyurethane foam layer is greater than 30mm, and the grid cloth The thickness of the mortar layer is 1.5-3mm.
The supporting structure for preventing heat transfer to surrounding rocks of a roadway according to claim 1, wherein the cross section of the roadway is rectangular, trapezoidal, semi-circular arch, arc arch, oval or circular.
According to any one of claims 1 to 3, a supporting structure for preventing heat transfer in surrounding rocks of a roadway, characterized in that barbs are provided on the grid cloth.