Construction method suitable for supporting small and medium-sized vertical shafts

Abstract

The invention belongs to the technical field of vertical shaft construction, particularly discloses a construction method suitable for supporting small and medium-sized vertical shafts, and aims to solve the problems that a traditional construction period is long, equipment mounting difficulty is high, and construction cost and potential safety hazards are increased. According to the method, well completion of a vertical shaft is completed firstly, a chute is drilled out, a baffle is installed, then the shaft is filled with slag stones, then a steel formwork is installed, concrete is poured between the shaft wall and the steel formwork, after the strength of the concrete meets the requirement, the baffle is opened, slag stones in the shaft and the chute are subjected to 4-m-height slag discharging, and then the slag stones in the shaft and the chute are discharged. And then a steel formwork is installed at the height of 4 m after deslagging, then concrete is poured, after the concrete meets the requirement, a ladder compartment is installed on the shaft wall, operation is cyclically repeated, and deslagging, formwork erecting and ladder compartment installation at the height of 4 m are completed every time till all construction procedures of the whole vertical shaft are completed. Supporting and ladder compartment integrated operation is achieved, traditional construction is converted into circulating construction, and the construction period is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shaft construction, in particular to a construction method suitable for small and medium-sized shaft support. BACKGROUND

[0002] As an important structure in underground engineering, shafts are widely used in mines, tunnels, underground pipe corridors and other engineering, mainly for personnel passage, equipment transportation and ventilation and drainage. For small and medium-sized shafts with a diameter of 3m and a height of 60m, the traditional construction method usually adopts the mode of segmented excavation- segmented support- segmented installation of equipment, that is, the shaft is excavated from top to bottom in sections, and concrete support is carried out in time after each section is excavated. After the entire shaft support is completed, the equipment such as ladder interval is installed from top to bottom or from bottom to top.

[0003] However, the traditional construction method is independent of support and equipment installation, and the construction period is long. For a shaft with a height of 60m, the construction period of the traditional method usually needs 3-4 months, and the equipment installation is difficult. Temporary scaffolding needs to be set up when installing the ladder interval in the later stage, which increases the construction cost and safety hazards. SUMMARY

[0004] The purpose of the present application is to provide a construction method suitable for small and medium-sized shaft support, to solve the problems of long construction period, difficult equipment installation, and increased construction cost and safety hazards of the traditional construction method.

[0005] To achieve the above-mentioned purpose, the basic scheme provided by the present application is: a construction method suitable for small and medium-sized shaft support, comprising the following steps: S1, using a raise boring machine to complete the shafting of the shaft, and drilling a chute connected with the roadway from the bottom of the shaft, the inclination angle of the chute is 45°, and a baffle is installed at the tail end of the chute, and an infrared material level monitoring device is installed at the top of the shaft; S2, filling slag in the shaft after shafting, using layered tamping method during filling, each layer tamping thickness ≤50cm, ensuring that the filling density ≥1.8t / m 3 , filling to the top surface of the slag and reserving 4m height at the wellhead; S3, installing a steel formwork at the reserved 4m height at the wellhead, the height of the steel formwork is flush with the wellhead, and a ring space of 25cm is reserved between the shaft wall and the steel formwork; S4, pouring concrete into the ring space reserved between the shaft wall and the steel formwork through a concrete mixer, and vibrating during pouring using an insert vibrator, the vibrating interval ≤50cm, ensuring that the concrete is dense, without honeycomb and pitted surface; S5, after pouring, the curing time is not less than 3 days, and the concrete strength reaches 70% of the design strength; S6. When the concrete strength reaches 70% of the design strength, remove the steel formwork, then slowly open the baffle to discharge the slag in the shaft and chute. The discharged slag is transported outward by the slag discharge truck in the roadway. When the infrared material level monitoring device shows that the slag discharge height reaches 4m, close the baffle. Then install the steel formwork at a height of 4m after slag discharge and pour concrete between the shaft wall and the steel formwork. After pouring, cure the concrete until the concrete strength reaches the design strength. S7. After the protective concrete reaches the design strength, remove the steel formwork, and then install the ladder room on the well wall according to the design drawings of the ladder room. After the installation of S8 and the ladder room is completed, repeat the S6-S7 cycle, completing the slag removal, formwork support and ladder room installation at a height of 4m each time, until all construction procedures of the entire shaft are completed.

[0006] The beneficial effects of this invention are as follows: it realizes the integrated operation of support and ladder installation, transforms the traditional segmented construction into cyclical continuous construction, significantly shortens the construction period, temporarily supports the well wall with slag and stone, and forms the initial support in conjunction with the overall pouring, reducing the risk of well wall collapse. The equipment installation and support are carried out simultaneously, eliminating the need to erect temporary scaffolding, reducing the risk of high-altitude operations and the cost of temporary facilities.

[0007] Option 2, which is the preferred option of the basic option, involves using a laser plumb bob to detect the verticality of the shaft in real time during the construction of the shaft, controlling the verticality deviation to ≤0.5%, ensuring that the inner wall of the shaft is flat and without obvious protrusions or depressions; using a laser plumb bob to control the verticality of the shaft in real time ensures that the shaft wall is flat, which is beneficial to the subsequent formwork installation and concrete pouring quality, and improves the overall integrity and safety of the support structure.

[0008] Option 3, which is the preferred option of the basic option, in S2, the particle size of the filling slag is controlled between 5 and 20 cm, the mud content in the slag is ≤3%, and the compressive strength is ≥30 MPa; the particle size, mud content and compressive strength of the slag are strictly controlled to ensure that the filling body has good support and permeability, enhance the temporary support effect on the well wall, and reduce the risk of lateral pressure during the concrete pouring process.

[0009] Option 4 is the preferred option of the basic option. In S3, the outer side of the steel formwork is fixed with diagonal bracing. The diagonal bracing on the outer side of the steel formwork enhances the stability of the formwork and prevents the formwork from shifting or deforming during the pouring process.

[0010] Option 5, the preferred option of the basic scheme, involves controlling the concrete pouring speed in S4 to be between 10 and 15 m / s. 3 / h; control the concrete pouring speed to 10-15m / h; 3 / h, combined with vibration technology, ensures that the concrete is fully compacted, avoids defects such as cold joints and honeycomb, and improves the overall strength and durability of the support structure.

[0011] Option 6 is the preferred option of the basic option. In S6, the slag discharge speed is controlled at 0.5 to 1 m / h. The slag discharge speed is controlled at 0.5 to 1 m / h to release the slag slowly, so as to avoid impact damage to the already poured concrete well wall and protect the integrity of the initial support structure.

[0012] Option 7, which is the preferred option of the basic option, in S6, the steel formwork is made up of several 40cm wide ring steel plates embedded in each other. The top ring steel plate has a pouring port for pouring concrete. After the concrete is poured, the pouring port will be sealed. The steel formwork adopts a combination of multiple ring steel plates embedded in each other, with a pouring port at the top, which facilitates concrete pouring and subsequent sealing, and improves the efficiency of formwork support and dismantling.

[0013] Option 8, an optimal choice from the basic option, involves installing the ladder in S7 as follows: Drill holes using an impact drill, then install the supports onto the well wall using M16 expansion bolts. The bolt embedment depth should be ≥10cm, and each support should be secured with at least two expansion bolts to ensure a support load capacity ≥5kN. Next, fix the ladder to the supports. The ladder uses 80×12 flat steel and L40×4 angle steel, with a step spacing of 30cm and a cross brace width of 25cm. The platform uses 6mm thick checkered steel plate, with dimensions of 1m×0.8m, and a guardrail is hung along the platform edge. This installation is secure and reliable, improving safety and achieving integrated installation of support and equipment. Attached Figure Description

[0014] Figure 1 This is a top view of the shaft in this invention; Figure 2 This is a construction drawing of the vertical shaft support in this invention. Detailed Implementation

[0015] The present invention will be further described in detail below through specific embodiments: The reference numerals in the accompanying drawings include: 1. Concrete layer; 2. Infrared material level monitoring device; 3. Roadway; 4. Baffle; 5. Chute; 6. Shaft; 7. Ladder compartment; 8. Steel formwork.

[0016] like Figure 1 and 2 As shown: A construction method suitable for the support of small and medium-sized vertical shafts, including the following steps: S1. A riser drilling rig is used to complete the vertical shaft 6 in one operation. During the construction process, a laser plumb bob is used to detect the verticality of the shaft in real time and control the verticality deviation to ≤0.5%. This ensures that the inner wall of the shaft 6 is flat and without obvious protrusions or depressions. Then, a chute 5 connected to the roadway 3 is drilled from the bottom of the shaft 6. The inclination angle of the chute 5 is 45°. A baffle 4 is installed at the tail end of the chute 5. An infrared material level monitoring device 2 is installed at the top of the vertical shaft 6. S2. Fill the wellbore 6 with slag after well completion. The particle size of the slag should be controlled between 5 and 20 cm, the mud content in the slag should be ≤3%, and the compressive strength should be ≥30 MPa. The filling should be carried out using a layered compaction method, with each layer ≤50 cm thick, ensuring a filling density ≥1.8 t / m³. 3 The slag is filled to a height of 4m between the top surface of the slag and the wellhead. The slag forms a supporting structure inside the well shaft 6 to prevent the well wall from collapsing. S3. Install steel formwork 8 at a height of 4m reserved at the wellhead. The outside of steel formwork 8 is fixed with diagonal bracing. The height of steel formwork 8 is flush with the wellhead. A 25cm annular space is reserved between the well wall and steel formwork 8. S4. Concrete (concrete layer 1) is poured into the annular space reserved between the well wall and the steel formwork 8 using a concrete mixer. The pouring speed of the concrete is controlled at 10-15m / s. 3 / h, during the pouring process, an immersion vibrator is used for compaction, with a vibration spacing of ≤50cm, to ensure that the concrete is dense and free of honeycomb and pitting; S5. After pouring, the curing time shall not be less than 3 days, until the concrete strength reaches 70% of the design strength; S6. When the concrete strength reaches 70% of the design strength, remove the steel formwork 8, then slowly open the baffle 4 to discharge the slag in the shaft 6 and chute 5. The slag discharge speed is controlled at 0.5-1m / h to avoid the concrete of the shaft wall being damaged by the impact due to excessively fast discharge. The discharged slag enters the hopper of the slag discharge truck in the tunnel 3 for outward transportation. When the infrared material level monitoring device 2 shows that the slag discharge height reaches 4m, close the baffle 4, and then install the steel formwork 8 at a height of 4m after slag discharge. The steel formwork 8 is made up of several ring steel plates with a width of 40cm that are interlocked. The top ring steel plate has a pouring port for pouring concrete. Concrete is poured from the pouring port into the space between the shaft wall and the steel formwork 8. After the last concrete is poured, the pouring port is sealed. After the pouring is completed, curing is carried out until the concrete strength reaches the design strength. S7. After the protective concrete reaches the design strength, remove the steel formwork 8. Then, according to the design drawings of the ladder room 7, install the ladder room 7 on the well wall. Specifically, first, drill holes with an impact drill, and then install the supports on the well wall with M16 expansion bolts. The bolt embedding depth is ≥10cm. Each support is fixed with at least 2 expansion bolts to ensure that the support bearing capacity is ≥5kN. Then, fix the ladder on the support. The ladder is made of 80×12 flat steel and L40×4 angle steel. The step spacing is 30cm, the cross brace width is 25cm, the platform is made of 6mm thick checkered steel plate, the platform size is 1m×0.8m, and the platform edge is hung with guardrails. After S8 and ladder room 7 are installed, repeat the S6-S7 cycle, completing the slag removal, formwork support and ladder room 7 installation at a height of 4m each time, until all construction procedures of the entire shaft are completed.

[0017] This invention adopts a one-time shaft construction + segmented support + segmented equipment installation mode, integrating the traditionally separate support and equipment installation processes. The construction cycle of a 60m vertical shaft can be shortened to 1.5 to 2 months, which is more than 30% shorter than the traditional method. At the same time, the initial support is formed by filling with slag and casting as a whole, which effectively prevents the shaft wall from collapsing. The slag discharge speed can be controlled in segments to avoid impact damage. The equipment installation does not require the erection of temporary scaffolding, reducing the risk of working at height.

[0018] In summary, integrated operations reduce process changeover time and investment in temporary facilities; waste rock can be used to reduce material costs; and the shortened construction cycle reduces labor and machinery rental costs, resulting in an overall cost reduction of 20-25%. The shaft size, support thickness (concrete layer), and ladder parameters can be adjusted according to actual project needs, making it suitable for small and medium-sized vertical shaft construction in mines, tunnels, underground utility tunnels, and other fields.

[0019] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A construction method suitable for supporting small and medium-sized vertical shafts, characterized in that, Includes the following steps: S1. A riser drilling rig is used to complete the shaft in one go, and a chute connected to the roadway is drilled from the bottom of the shaft. The chute has an inclination angle of 45° and a baffle is installed at the end of the chute. An infrared material level monitoring device is installed at the top of the shaft. S2. Fill the wellbore with slag and rock after well completion. Use a layered compaction method, with each layer ≤50cm thick, ensuring a filling density ≥1.8t / m³. 3 Fill to a height of 4m between the top surface of the slag and the wellhead; S3. Install steel formwork at a height of 4m reserved at the wellhead. The height of the steel formwork should be flush with the wellhead. Leave a 25cm annular space between the well wall and the steel formwork. S4. Concrete is poured into the annular space reserved between the well wall and the steel formwork using a concrete mixer. During the pouring process, an immersion vibrator is used for compaction with a vibration interval of ≤50cm to ensure that the concrete is dense and free of honeycomb and pitting. S5. After pouring, the curing time shall not be less than 3 days, until the concrete strength reaches 70% of the design strength; S6. When the concrete strength reaches 70% of the design strength, remove the steel formwork, then slowly open the baffle to discharge the slag in the shaft and chute. The discharged slag is transported outward by the slag discharge truck in the roadway. When the infrared material level monitoring device shows that the slag discharge height reaches 4m, close the baffle. Then install the steel formwork at a height of 4m after slag discharge and pour concrete between the shaft wall and the steel formwork. After pouring, cure the concrete until the concrete strength reaches the design strength. S7. After the protective concrete reaches the design strength, remove the steel formwork, and then install the ladder room on the well wall according to the design drawings of the ladder room. After the installation of S8 and the ladder room is completed, repeat the S6-S7 cycle, completing the slag removal, formwork support and ladder room installation at a height of 4m each time, until all construction procedures of the entire shaft are completed.

2. The construction method for supporting small and medium-sized vertical shafts according to claim 1, characterized in that, In S1, a laser plumb bob is used to detect the verticality of the shaft in real time during the construction process, and the verticality deviation is controlled to be ≤0.5%, ensuring that the inner wall of the shaft is flat and without obvious protrusions or depressions.

3. The construction method for supporting small and medium-sized vertical shafts according to claim 1, characterized in that, In S2, the particle size of the filling slag is controlled between 5 and 20 cm, the mud content in the slag is ≤3%, and the compressive strength is ≥30 MPa.

4. The construction method for supporting small and medium-sized vertical shafts according to claim 1, characterized in that, In S3, the outer side of the steel formwork is fixed with diagonal bracing.

5. A construction method for supporting small and medium-sized vertical shafts according to claim 1, characterized in that, In S4, the concrete pouring speed is controlled at 10-15m / s. 3 / h.

6. A construction method for supporting small and medium-sized vertical shafts according to claim 1, characterized in that, In S6, the slag discharge speed is controlled at 0.5 to 1 m / h.

7. A construction method for supporting small and medium-sized vertical shafts according to claim 1, characterized in that, In S6, the steel formwork is made up of several 40cm wide ring steel plates that are interlocked. The top ring steel plate has a pouring port for pouring concrete. After the concrete is poured, the pouring port is sealed.

8. A construction method for supporting small and medium-sized vertical shafts according to claim 1, characterized in that, In S7, the method for installing the ladder is as follows: drill holes with an impact drill, then install the supports on the well wall with M16 expansion bolts. The bolt embedding depth is ≥10cm. Each support is fixed with at least 2 expansion bolts to ensure that the support bearing capacity is ≥5kN. Then fix the ladder on the support. The ladder is made of 80×12 flat steel and L40×4 angle steel. The step spacing is 30cm and the cross brace width is 25cm. The platform is made of 6mm thick checkered steel plate. The platform size is 1m×0.8m. The platform edge is covered with guardrails.

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