A rotary drilling construction device for open-pit vertical shaft guide shafts

Abstract

This utility model discloses an open-pit vertical shaft guide shaft rotary drilling construction device, including a rotary drilling rig, a drill bit, a steel casing, a foundation treatment layer, a wellhead sealing structure, a steel plate well cover, pre-anchor bolt support, and a steel arch support. The rotary drilling rig is installed on the foundation treatment layer, and the drill bit is connected to the rotary drilling rig via a drill rod. The steel casing is located at the wellhead, and the drill rod passes through the steel casing. The wellhead sealing structure consists of a concrete pad and brick walls, forming a flat plate structure, and is installed on both sides of the wellhead. The steel plate well cover covers these structures to seal the wellhead. The pre-anchor bolt support is located at the top of the intersection of the guide shaft and the lower passage, and the steel arch support is installed inside the lower passage and fixedly connected to the pre-anchor bolt support. This utility model's open-pit vertical shaft guide shaft rotary drilling construction device has a simple structure, is easy to use, and can achieve safe and efficient construction of vertical shaft guide shafts, enhancing the stability of the wellhead and intersection.

Description

Technical Field

[0001] This utility model belongs to the field of water conservancy and hydropower engineering construction technology, specifically relating to an open-pit vertical shaft guide shaft rotary drilling construction device. Background Technology

[0002] Currently, the construction of vertical shaft pilot shafts mostly adopts the reverse-pull drilling process using a raise boring machine. Although this process is technically mature and safe, it has significant drawbacks: high equipment mobilization and demobilization costs, complex installation and dismantling procedures leading to long construction cycles; extensive preparatory work such as ventilation, water, electricity, and foundation treatment increases construction costs; frequent installation and dismantling of raise boring machines reduces equipment utilization when there are many vertical shafts and they are concentrated in one area; and the raise boring machine can only be used if the lower channel is already connected, which limits the construction sequence and overall schedule.

[0003] To address the aforementioned issues, rotary drilling rigs have been gradually introduced in engineering practice to replace raise shaft drilling rigs. Rotary drilling rigs are widely used in building pile foundations, bridge pile foundations, and municipal foundation engineering, offering advantages such as mobility, high drilling efficiency, and good construction safety. However, in the field of vertical shaft and guide shaft construction in hydropower projects, the application of rotary drilling rigs is still in the exploratory stage, lacking specialized equipment structures and supporting processes tailored to the characteristics of vertical shafts.

[0004] Therefore, there is an urgent need for an open-pit vertical shaft guide shaft rotary drilling construction device with a reasonable structure, compact layout, convenient construction, and adaptability to different geological conditions, in order to solve the problems of high construction cost, long cycle and many dependent conditions of traditional reverse drilling rig technology, and to achieve safe, efficient and economical construction of vertical shaft guide shafts. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide an open-pit vertical shaft guide shaft rotary drilling construction device that has a reasonable structure, compact layout, convenient construction, and can adapt to different geological conditions.

[0006] The technical solution of this utility model is as follows: An open-pit vertical shaft pilot shaft rotary drilling construction device includes: a rotary drilling rig, a drill bit, a steel casing, a foundation treatment layer, a wellhead sealing structure, a steel plate well cover, advanced anchor bolt support, and a steel arch support. The rotary drilling rig is installed on the foundation treatment layer, which is located on one side of the wellhead. The drill bit is connected to the rotary drilling rig via a drill rod. The steel casing is installed at the wellhead, and the drill rod passes through the steel casing. The wellhead sealing structure is composed of a concrete pad and a brick wall and is a flat plate structure. Two wellhead sealing structures are respectively installed on both sides of the wellhead. The steel plate well cover is placed on the wellhead sealing structure to seal the wellhead. The advanced anchor bolt support is installed at the top of the intersection of the pilot shaft and the lower passage. The steel arch support is installed in the lower passage and is fixedly connected to the advanced anchor bolt support.

[0007] Furthermore, the drill bit is a replaceable structure, including a barrel drill bit, a rock-socketing drill bit, and an impact drill bit.

[0008] Furthermore, the steel casing is buried at a greater depth in soft soil than it is buried in rock foundation.

[0009] Furthermore, the foundation treatment layer is formed by a crushed stone cushion layer, and steel plates are laid on the crushed stone cushion layer or concrete is used for hardening treatment.

[0010] Furthermore, the diameter of the drill bit is selected within the range of 1.5m to 3.0m.

[0011] Furthermore, the advanced anchor bolt support and steel arch support are arranged within a 120° range of the top arch of the lower passage.

[0012] The beneficial effects of this utility model are: Compared to existing reverse-pull drilling technology, this invention offers significant advantages such as a reasonable structure, high construction efficiency, and safety. Firstly, this device utilizes a rotary drilling rig for pilot well drilling, eliminating the need for specialized ventilation, water, and electricity systems or large foundation platforms; only ground leveling is required before construction can commence, greatly simplifying preparation work. Secondly, the rotary drilling rig boasts excellent mobility and reusability, allowing for rapid movement between multiple shaft positions without repeated disassembly and reassembly, significantly improving equipment utilization and construction efficiency. The steel casing and wellhead sealing structure effectively prevent wellhead collapse and rainwater intrusion, enhancing wellhead stability and construction efficiency. Safety: The wellhead sealing structure adopts a combination design of concrete pad, brick wall and steel plate well cover, which is reliable and easy to disassemble. It can prevent debris from falling in and facilitate secondary construction after the passage is completed. At the intersection of the pilot shaft and the lower passage, the device forms a composite reinforcement system by setting advanced anchor bolt support and steel arch support, which can effectively prevent top blockage and collapse and improve the overall structural safety. In addition, the drill bit assembly can be flexibly replaced according to different rock strata conditions, which is highly adaptable and can meet the construction needs of different geological environments. In summary, this utility model can significantly reduce the cost and cycle of vertical shaft pilot shaft construction, improve safety and economy, and has high engineering promotion and application value. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the usage status of an open-pit vertical shaft guide shaft rotary drilling construction device according to this utility model.

[0014] Figure 2 This is a schematic diagram of the wellhead sealing structure of an open-pit vertical shaft guide shaft rotary drilling construction device according to this utility model.

[0015] Figure 3This is a schematic diagram of the advanced anchor bolt support structure of an open-pit vertical shaft guide shaft rotary drilling construction device according to this utility model.

[0016] Figure 4 This is a flowchart illustrating the usage steps of an open-pit vertical shaft guide shaft rotary drilling construction device according to this utility model.

[0017] In the diagram: 1-Vertical shaft, 2-Guide shaft, 3-Lower passage, 4-Rotary drilling rig, 5-Steel casing, 6-Drill bit, 7-Foundation treatment layer, 8-Unexcavated part, 9-Wellhead sealing structure, 10-Steel plate well cover, 11-Advanced anchor bolt support, 12-Steel arch support. Detailed Implementation

[0018] like Figure 1-4As shown, an open-pit vertical shaft pilot shaft rotary drilling construction device includes a rotary drilling rig 4, a drill bit 6, a steel casing 5, a foundation treatment layer 7, a wellhead sealing structure 9, a steel plate well cover 10, an advanced anchor bolt support 11, and a steel arch support 12. The rotary drilling rig 4 is installed on the foundation treatment layer 7 and is used to drive the drill bit 6 to perform vertical rotary drilling construction. The foundation treatment layer 7 is located on one side of the shaft wellhead and is used to provide a stable working platform for the rotary drilling rig 4. The foundation treatment layer 7 preferably adopts a crushed stone cushion layer structure, and its surface... The surface is reinforced with steel plates or hardened with concrete to enhance load-bearing capacity and anti-settlement performance. The drill bit 6 is connected to the rotary drilling rig 4 via a drill rod and can be replaced according to different geological conditions. Preferably, the drill bit 6 includes three types: a barrel drill bit, a rock-socketed drill bit, and an impact drill bit, which can be applied to different geological conditions such as gravel layers, moderately weathered sandstone layers, and slightly weathered granite layers, to improve drilling efficiency and borehole wall forming quality. The diameter of the drill bit 6 can be selected from 1.5m to 3.0m according to design requirements. Within the specified range; the steel casing 5 is installed at the shaft opening, with its lower end buried in the stratum, used for positioning and guiding the borehole opening and preventing it from collapsing; to adapt to different geological conditions, the steel casing 5 is buried at a greater depth in soft soil than in rock foundation conditions, to improve the stability and guiding accuracy of the wellhead; the wellhead sealing structure 9 is composed of a concrete cushion layer and a brick wall, forming a flat plate structure, with two wellhead sealing structures 9 respectively arranged on both sides of the wellhead, used for safe sealing of the wellhead during construction completion or suspension phases, the concrete cushion layer for load-bearing and fixation, and the brick wall portion for forming the enclosure structure; the steel plate The manhole cover 10 horizontally covers the manhole sealing structure 9 to seal the wellhead of the guide well, preventing rainwater and debris from entering the well and ensuring construction safety. The advanced anchor bolt support 11 is set at the top of the intersection of the guide well and the lower passage, which can pre-reinforce the intersection before the lower passage is completed. The steel arch support 12 is arranged inside the lower passage and is fixedly connected to the advanced anchor bolt support 11. The two together form a composite support system to improve the overall stability and anti-collapse ability of the intersection of the guide well and the lower passage. Preferably, the advanced anchor bolt support 11 and the steel arch support 12 are both arranged within the 120° range of the top arch of the lower passage to form key reinforcement of the weak area at the top.

[0019] Through the above design, this utility model not only improves the safety and efficiency of vertical shaft pilot shaft construction, but also reduces the dependence of traditional raise shaft drilling rigs on construction site, water and electricity conditions and the conditions for connecting the lower passage. The overall construction cycle is short, the cost is low, and the adaptability is strong, which has good promotion and application value.

[0020] During the construction of the vertical shaft pilot shaft, the open-pit vertical shaft pilot shaft rotary drilling construction device of this utility model is used, and the following steps are followed in sequence: Step 1: Equipment Selection and Layout: Based on the design dimensions, depth, and geological conditions of the vertical shaft, determine the required rotary drilling rig 4 model, drill bit 6 type, and guide shaft diameter. The rotary drilling rig 4 is placed on the foundation treatment layer 7. The foundation treatment layer 7 forms a stable construction platform through a crushed stone cushion layer, steel plate, or concrete hardening layer. The steel casing 5 is pre-embedded at the wellhead position to guide the drill rod and keep the borehole stable. Depending on different geological conditions, a bucket drill bit, rock-socketed drill bit, or impact drill bit can be selected to achieve efficient rock breaking operations.

[0021] Step 2, Site Preparation and Equipment Placement: Before the drilling rig enters the site, the construction site is leveled to ensure that the bearing capacity and flatness of the foundation meet the construction requirements. After determining the center position of the guide shaft by measurement and layout, the rotary drilling rig 4 is accurately placed and the verticality of the drill rod is adjusted so that the center of the drill rod is coaxial with the steel casing 5.

[0022] Step 3, Drilling: Start the rotary drilling rig 4 and drive the drill bit 6 to rotate and break the rock. During the drilling process, the drill bit is connected to the rotary drilling rig 4 through the drill rod and transmits torque to realize the breaking of rock and soil and the lifting of slag. To ensure the quality of the hole wall, the drill bit 6 can be replaced in order from small diameter to large diameter to enlarge the hole until the design depth is reached.

[0023] Step 4, Hole Cleaning Operation: After the hole is formed, the lifting and stirring functions of the rotary drilling rig 4 are used to clean the bottom of the hole. The sediment at the bottom of the hole is stirred and pulled out of the hole by using a sand scoop or air blowing cleaning process. This is repeated until the thickness of the sediment at the bottom of the hole is less than 100mm, ensuring that the bottom of the hole is clean and the hole depth meets the standard.

[0024] Step 5, Wellhead Sealing: After the well is cleaned, install the wellhead sealing structure 9 and the steel plate well cover 10. The wellhead sealing structure 9 consists of a concrete pad and a brick wall. Two wellhead sealing structures 9 are set on both sides of the wellhead to form a closed support platform. The concrete pad is about 20cm thick and the brick wall is about 80cm high. The steel plate well cover 10 is horizontally placed above the wellhead with a thickness of 1-2cm to prevent rainwater and debris from entering the well and to prevent personnel from accidentally entering, ensuring construction safety.

[0025] Step Six: Support at Intersections When the lower passage 3 is excavated to a distance of about 5m from the guide shaft 2, the guide shaft 2 is inspected. After confirming that there is no water accumulation, collapse or other abnormalities, it is reinforced. Advanced anchor bolt support 11 and steel arch support 12 are deployed within the 120° range of the top arch of the lower passage 3 to form a stable composite support system, so as to enhance the overall bearing capacity and anti-collapse performance of the intersection.

[0026] Through the above operations, the construction device of this utility model can realize the rapid, efficient and safe construction of vertical shaft pilot shafts. Compared with the traditional reverse drilling rig reverse pulling process, this device can independently complete the pilot shaft construction without the need for the lower channel to be connected, which greatly reduces the construction preparation time and equipment installation workload, significantly improves construction efficiency and safety, and reduces the overall project cost.

[0027] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A rotary drilling construction device for open-pit vertical shaft guide shafts, characterized in that, include: The rotary drilling rig (4), drill bit (6), steel casing (5), foundation treatment layer (7), wellhead sealing structure (9), steel plate well cover (10), advanced anchor bolt support (11), and steel arch support (12) are provided. The rotary drilling rig (4) is set on the foundation treatment layer (7), which is located on one side of the wellhead. The drill bit (6) is connected to the rotary drilling rig (4) through a drill rod. The steel casing (5) is set at the wellhead position, and the drill rod passes through... The steel casing (5), the wellhead sealing structure (9) is composed of a concrete pad and a brick wall and is a flat plate structure. The two wellhead sealing structures (9) are respectively set on both sides of the wellhead. The steel plate well cover (10) is placed on the wellhead sealing structure (9) to seal the wellhead. The advanced anchor bolt support (11) is set at the top of the intersection of the guide well and the lower channel. The steel arch support (12) is set in the lower channel and is fixedly connected to the advanced anchor bolt support (11).

2. The rotary drilling construction device for open-pit vertical shaft guide shafts according to claim 1, characterized in that, The drill bit (6) is a replaceable structure, including a barrel drill bit, a rock-socketing drill bit, and an impact drill bit.

3. The rotary drilling construction device for open-pit vertical shaft guide shafts according to claim 1, characterized in that, The steel casing (5) is buried at a greater depth in the soft soil layer than it is buried in the bedrock.

4. The rotary drilling construction device for open-pit vertical shaft guide shafts according to claim 1, characterized in that, The foundation treatment layer (7) is formed by a crushed stone cushion layer, and steel plates are laid on the crushed stone cushion layer or concrete is hardened.

5. The rotary drilling construction device for open-pit vertical shaft guide shafts according to claim 1, characterized in that, The diameter of the drill bit (6) is selected in the range of 1.5m to 3.0m.

6. The rotary drilling construction device for open-pit vertical shaft guide shafts according to claim 1, characterized in that, The advanced anchor bolt support (11) and the steel arch support (12) are arranged within a 120° range of the top arch of the lower passage.

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