A method for constructing kilometer-level bedrock leveling benchmarks to control borehole inclination

Abstract

This invention discloses a method for constructing kilometer-level bedrock benchmarks with controlled borehole inclination, employing a series of new technologies including inverted drilling, vertical benchmark control, mud slurry wall protection, and vacuum benchmark fixing. The main steps include: A) site leveling within the project area; B) vertical installation, stability testing, and mud pumping of the drilling rig; C) inverted drilling with light pressure and slow rotation of large-diameter drill bits, with timely monitoring of borehole inclination; D) use of vacuum benchmark fixing technology and a new type of wall-protecting mud slurry; E) drilling with variable drilling pressure and speed using small-diameter drill bits; F) installation of a steel ring-shaped tray at the bottom of the borehole; G) benchmark installation, borehole depth correction, and borehole inclination control; H) installation of main and auxiliary benchmark heads, construction of protective exteriors, and observation of the relative settlement of the bedrock benchmark, wall protection pipe, and protective structure using a differential pressure hydrostatic level. Kilometer-level bedrock benchmarks are rare both domestically and internationally. This discussion of site leveling, construction, borehole inclination control, and level instrument installation provides valuable experience for subsequent construction.

Description

Technical Field

[0001] This invention relates to the field of engineering geological leveling surveying, and in particular to a method for constructing a kilometer-level bedrock leveling benchmark to control borehole inclination. Background Technology

[0002] Currently, China has accumulated considerable experience and achieved excellent results in the construction of bedrock benchmarks. However, due to complex geological conditions, the Quaternary loose deposits in the Tianjin area are nearly 1,000 meters thick, making the construction of bedrock benchmarks extremely difficult. Bedrock benchmarks exceeding 1,000 meters in depth are rare both domestically and internationally. The deepest bedrock benchmark in Osaka, Japan, reaches 600 meters. The Liqizhuang bedrock benchmark, established by the Tianjin Surveying and Mapping Institute, is an important leveling point in Tianjin, with a base depth of 1,088 meters, which was once among the world's deepest. The improvement of the Haihe River Basin elevation system requires four 1,000-meter-level bedrock benchmarks, to be constructed at the Tuanpowa Reservoir, Qingyun Hydrological Station, Xianxian Hydrological Station, and Xingaifang Hydrological Station. The final benchmark depths are 1147.63 meters, 1240.18 meters, 1196.58 meters, and 1553.66 meters, respectively. It is estimated that these four bedrock benchmarks will rank among the top four in the world for a considerable period. In addition, these four bedrock markers need to form a bedrock marker leveling control network in the eastern plain area of ​​the lower reaches of the Haihe River Basin together with the seven existing bedrock markers in Yanshankou, Tangshan, Jixian, Baodi, Tianjin Liqizhuang, Cangzhou, and Dezhou. The length of the leveling route in the region should not exceed 100 kilometers, and it should also meet the requirements of watershed hydrological monitoring, water conservancy project construction and management for leveling accuracy.

[0003] Because the construction of kilometer-level bedrock benchmarks is quite difficult, and there are no corresponding technical standards for bedrock benchmarks exceeding 1000 meters, geological exploration and data analysis should be carried out at the proposed bedrock benchmark site before construction. This is to scientifically determine the bedrock benchmark stations that meet the requirements for leveling and stability, and to formulate specific construction technical plans. In the past, bedrock benchmarks were often constructed using layered benchmarks, which were not technically sophisticated and made it difficult to guarantee borehole inclination. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a method for constructing kilometer-level bedrock leveling markers to control borehole inclination, so that engineers can construct bedrock markers in areas with deep overburden and then carry out leveling work.

[0005] The solution adopted by this invention to solve the above-mentioned technical problems is: a method for constructing a kilometer-level bedrock leveling beacon to control borehole inclination, comprising the following steps:

[0006] Step A: Leveling the foundation layer of the engineering area, vertical installation of drilling equipment, and securing the drilling tower;

[0007] Step B: Use a large-diameter drill bit with light pressure and slow rotation to drill a reverse hole, while also taking into account the lithological characteristics;

[0008] Step C: Use seamless steel pipe cementing with threaded connections for well protection. The bottom is sealed with welded steel plates. Mud is injected between the protective pipe and the borehole wall. After the mud solidifies, the drill pipe is pulled out.

[0009] Step D: Drill the bottom hole using a small-diameter drill bit with varying drill pressure and drilling speed, and measure relevant parameters after well completion;

[0010] Step E: Install the steel ring-shaped tray at the bottom of the drill hole;

[0011] Step F, Installation of kilometer-level bedrock marker poles: Before lowering the pipe, the hole depth is corrected, and the pipe lowering work is completed in one go using the wire rope lifting method. To ensure the verticality of the marker pole, a straightener is added. After lowering the pipe, cement grout is injected into the marker pole, and the pressure drop method using a check valve is used to fix the marker.

[0012] Step G: Installation of the main and auxiliary benchmarks for the bedrock leveling system and construction of protective exterior decorations; embedding the benchmark information in the walls of the benchmark building; using a differential pressure hydrostatic level to observe the relative settlement of the bedrock benchmark, retaining pipe, and protective building.

[0013] Step A specifically includes:

[0014] Step A1: The total area of ​​the construction site shall not be less than 25m×25m. The site shall be leveled. Loose strata shall be poured with cement and then drill tower timber shall be added. Drill tower timber shall be installed directly on hard strata.

[0015] Step A2: Place the drilling rig on the ground beam, aligning the center of the turntable with the center of the drilling tower's overhead beam. Fix and level the drilling rig and the ground beam, ensuring that the overhead crane, pulley, and turntable center are in a straight line.

[0016] Step A3: After the drilling rig is erected, it should be secured on all four sides with windproof ropes or steel wires, and the angle with the ground should not exceed 45 degrees. The ends of the ropes should be fastened with clips.

[0017] Step B employs inverted hole drilling technology, combined with pressure and rotation speed control, specifically including:

[0018] Step B1: Select the appropriate drill bit type according to the lithology of the formation. In soft upper formations, use milling tooth drill bits; in hard formations, use insert tooth drill bits; in easily inclined formations, use roller cone drill bits with small offset, no gauge protection teeth, or many short teeth.

[0019] Step B2: The drilling pressure is adjusted to achieve the breaking strength value of the rock being drilled, and is selected in combination with the equipment capacity and drill bit strength. 3kN / cm to 4kN / cm is used for drilling in medium to hard rock formations, and 1kN / cm to 3kN / cm is used for drilling in softer formations below medium to hard.

[0020] Step B3: The linear velocity of the drill bit's outer edge rotation is 0.8 m / s to 1.5 m / s, decreasing to 0.6 m / s when encountering gravel or severely fractured strata; the drilling speed is 80 r / min to 145 r / min when the strata are intact, the hardness is low, the borehole is shallow, and the speed is 30 r / min to 60 r / min when encountering fractured strata.

[0021] Step B4: The bottom pressure should not exceed two-thirds of the total weight of the drill collar. Use uniform drilling speed and light pressure with slow rotation. Control the verticality of the bedrock marker during the process. Drill to fresh, undisturbed bedrock, perform lithological analysis, and then continue drilling.

[0022] Step C specifically includes:

[0023] Step C1, Hole inclination: Use drill collars to apply pressure during drilling. The total mass of the drill collars should exceed the normal pressure value by 30%, and a stabilizer should be installed on the bottom drill collar. When encountering a soft-hard interface, use a smaller drill pressure to drill, and then increase the designed drill pressure to drill after passing through the interface.

[0024] Step C2: Monitor hole inclination. Monitor the hole inclination every 50m of drilling. If the verticality exceeds the specified value, correct the hole inclination.

[0025] Step C3: Use seamless steel pipes for cementing protection, and connect the protective pipes with threaded connections;

[0026] Step C4: Cut a slurry return hole at the bottom of the lowest casing. After the protective pipe is installed, lower the drill rod from inside the protective pipe to a distance above the bottom of the hole. Then, weld and fix the drill rod around the opening of the protective pipe with a steel plate.

[0027] Step C5: Using vacuum wall protection technology, the wall protection slurry is pumped into the hole through the drill pipe. Clean water or slurry enters the gap between the protective pipe and the hole wall and returns to the ground. After the circulation is normal, the well-mixed cement slurry is pumped into the hole from the drill pipe using a mud pump until cement slurry returns from the hole opening.

[0028] Step C6: Clean the drill pipe of any remaining cement slurry with clean water, let it stand for a period of time until the cement slurry solidifies, and then remove the drill pipe.

[0029] After the drill bit in step D contacts the bottom of the hole, it is first broken in for more than 0.5 hours at low drilling pressure and low rotation speed to form the bottom shape. Then, the drilling pressure and rotation speed are gradually increased to normal parameters. Finally, the relevant parameters of the well are measured, including temperature and well inclination.

[0030] The steel ring-shaped tray mentioned in step E is used to increase the contact area between the marker and the bedrock, and a certain amount of cement is poured in to solidify it with the rock, ensuring stability.

[0031] Step F specifically includes:

[0032] Step F1: Before lowering the pipe, perform hole depth correction and check the sequence and code of the marker pipes to ensure that the cumulative length of the marker poles matches the actual marking depth, and the error shall not exceed 1m;

[0033] Step F2: After the bottom of the marker pole is inserted into the hole of the steel support plate, the marker pole is installed. The lowering of the marker pole is completed in one go using the wire rope lifting method. The screws between the pipes are tightened to prevent them from falling off.

[0034] Step F3: When lowering the marker, add a ball bearing stabilizer every 8-10m to ensure the verticality of the marker.

[0035] Step F4: After the marker is in place, pour a measured amount of cement grout into the marker.

[0036] Step F5: The benchmark is fixed by pumping pressure drop using a check valve. Before fixing the benchmark, the inner and outer sleeve sealing devices are installed at the two-stage sleeve joint to ensure a reliable seal in the tubular annular gap of the overlapping part of the two-stage sleeves.

[0037] In step G, the main marker head is installed at the top of the marker pole, and the secondary marker head is installed on one side of the protective pipe and integrated with the protective pipe; a marker house is built to protect the marker body, and a marble slab with bedrock marker information is inlaid on one side of the marker house wall; multiple differential pressure static leveling sensors are installed, and monitoring data is transmitted to the network server in real time through a communication network.

[0038] The beneficial effects of this invention are as follows: Considering the high difficulty and technical requirements of constructing kilometer-level bedrock markers, which are rare both domestically and internationally, this invention adopts a series of new technologies such as inverted hole drilling, vertical control of the marker pole, mud slurry wall protection, and vacuum marker fixing. These technologies guide the site leveling and construction process in the construction of kilometer-level bedrock markers and control the inclination of the boreholes and the bedrock markers. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0040] The present invention provides a method for constructing kilometer-level bedrock leveling benchmarks to control borehole inclination, comprising the following steps:

[0041] Step A: Leveling of the foundation layer within the project area, vertical installation and stability testing of the drilling rig equipment, and mud pumping, specifically including:

[0042] Step A1: Level the soft / hard ground base layer within the project area. The total construction site area should be no less than 25m × 25m. The drilling rig installation foundation will be determined based on the base layer conditions to prevent the drilling rig from sinking during construction. For loose base layers, pour a cement base with the following material requirements: cement (500 grade): sand (coarse sand): aggregate (4-6 mm) = 1:2:3. For hard base layers, install the drilling rig timber directly on the leveled ground. The site layout needs to be rationally arranged according to the site orientation, including the drilling rig, mud pit, material yard, generator set, etc.

[0043] Step A2: Place the drilling rig on the ground beam, aligning the center of the turntable with the center of the drilling tower's overhead beam. Fix and level the drilling rig and the ground beam, ensuring that the overhead crane, pulley, and turntable center are in a straight line.

[0044] Step A3: After the drilling tower is erected, it must be fixed on all four sides with windproof ropes or steel wires, and the angle with the ground should not be greater than 45 degrees. The connection of the two ends of the rope should be secured with two buckles.

[0045] Step A4: Install the mud pump in a suitable location. The volume of the mud pit should be built according to the requirements. If the mud pump is far from the drilling rig, use steel pipes to fabricate high-pressure pipelines and connect them to the high-pressure pipeline near the drilling rig using flanges. A high-pressure valve and a return water valve should be installed at the outlet of the mud pump, with a certain distance between them.

[0046] Step B: Drilling with a φ246mm borehole diameter: The drilling tools, from bottom to top, consist of a φ246mm roller cone bit, a φ150mm drill collar, a φ73mm drill rod, and a drive drill rod. The drilling tools must be vertical and meet rigidity requirements. The bottom pressure should not exceed two-thirds of the total weight of the drill collar. Use a single-speed drilling method, applying light pressure and rotating slowly to ensure the verticality of the borehole. Drill through the Quaternary sedimentary layer, then through the paleoweathered bedrock zone. After reaching fresh, undisturbed bedrock, have a geological expert perform lithological analysis on the core sample before drilling for another 3 meters and stopping. This ensures the bottom of the bedrock marker pipe reaches stable bedrock to protect the marker from unstable strata. Overall pressure is controlled as follows: 0.5 tons within 0-50 meters; 1 ton within 50-100 meters; and 2 tons beyond 100 meters. The rotation speed is controlled at 65 revolutions per minute.

[0047] Step C: Cementing protection is achieved using seamless steel pipe with threaded connections. The bottom is sealed with welded steel plates, and mud is injected between the protective pipe and the borehole wall. After the mud solidifies, the drill pipe is removed. Specifically, this includes:

[0048] Step C1: Use a geological-specific DZ40 seamless steel pipe with a length of 12 meters, a diameter of 178 mm, and a wall thickness of 8 mm for cementing. The protective pipes are connected by threaded connections.

[0049] Step C2: Monitor hole inclination. Monitor the hole inclination every 50m of drilling. If the verticality exceeds the specified value, correct the hole inclination.

[0050] Step C3: Cut three 25 mm diameter return holes about 1 meter from the bottom of the bottom casing. After the protective pipe is installed, lower the drill rod from inside the protective pipe to a depth of 1 meter from the bottom of the hole. Then, weld and fix the drill rod around the opening of the protective pipe with steel plate.

[0051] Step C4: A cement slurry is prepared using water and cement to achieve a vacuum-fixed bedrock marker effect. Water or thin mud is pumped into the borehole through the drill pipe. The water or thin mud enters the gap between the protective pipe and the borehole wall and returns to the surface. After normal circulation, the mixed cement slurry is pumped into the borehole through the drill pipe using a mud pump until cement slurry returns to the borehole opening. The water-to-cement ratio is 1:2, and the specific gravity of the cement slurry is 1.8. The initial pumping pressure is 3 kPa, gradually increasing to 8 kPa as more cement slurry is added. The mud slurry uses a new formulation, with main components including: water, sodium carbonate, compound ammonium salts, carboxymethyl cellulose, yellow asphalt, 101 glue, soda ash, and caustic soda.

[0052] Step C5: Clean the drill pipe of any remaining cement slurry with an appropriate amount of water. After letting it stand for 4-6 hours and allowing the cement slurry to solidify, remove the drill pipe.

[0053] Step D: After cementing is completed, drilling continues using a φ130mm drill bit to install the marker rod at the bottom. The drill string assembly, from bottom to top, consists of a φ130mm roller cone bit, a φ150mm drill collar, a φ73mm drill pipe, and a drive drill pipe. After the drill bit contacts the bottom of the hole, it is first broken in at low drilling pressure and low rotation speed for at least 0.5 hours to create the bottom shape. After this, the drilling pressure and rotation speed are gradually increased to normal parameters. After drilling for another 3.3m, drilling is stopped, and the hole is cleaned in preparation for marker rod installation. Finally, relevant parameters of the completed well are measured, mainly including temperature and well inclination.

[0054] Step E: Install the steel ring-shaped tray at the bottom of the borehole; the steel ring-shaped tray is used to increase the contact area between the marker and the bedrock, and a certain amount of cement is poured in to solidify it with the rock, ensuring stability. The outer diameter of the tray is 10mm smaller than the diameter of the bedrock borehole, the thickness is 50mm, and a φ73mm hole is drilled at the bottom of the tray. The marker is made of φ73mm geological-grade DZ40 seamless steel pipe with a wall thickness of 5mm.

[0055] Step F, installation of kilometer-level bedrock markers, includes: pre-layout hole depth correction, completion of marker laying in one go using wire rope hoisting, addition of a stabilizer to ensure marker verticality, injection of cement grout into the marker after laying, and securing the marker using a check valve pump-in pressure drop method; specifically including:

[0056] Step F1: Before lowering the pipe, perform hole depth correction and check the sequence and code of the marker pipes to ensure that the cumulative length of the marker pole matches the actual depth of the marker, and the error shall not exceed 1 meter;

[0057] Step F2: After the bottom of the marker pole is inserted into the hole of the steel support plate, the marker pole is installed. The lowering of the marker pole is completed in one go using the wire rope lifting method. The screws between the pipes are tightened to prevent them from falling off.

[0058] Step F3: When lowering the marker, add ball bearing stabilizers at regular intervals to ensure the verticality of the marker. When the marker goes 500 meters underground, install a stabilizer every 5 meters; when it goes less than 500 meters underground, install a stabilizer every 10 meters.

[0059] Step F4: After the marker is in place, pour a fixed amount of cement grout with a grade of 500 and a water-cement ratio of 0.5 into the marker. The volume of the grout should be 80% of the actual volume of the bedrock section of the borehole.

[0060] Step F5: The marker is fixed using the check valve pump-in pressure drop method. Before fixing the marker, inner and outer sleeve sealing devices should be installed at the two-stage sleeve joint to ensure a reliable seal in the tubular annular gap of the overlapping part of the two-stage sleeves.

[0061] Step G: Installation of the main and auxiliary leveling heads for the bedrock leveling beacon. The main head is installed at the top of the beacon pole, and the auxiliary head is installed on one side of the protective pipe, integrated with the protective pipe. The main head is made of 1Cr18Ni9Ti stainless steel, in a hemispherical arc shape, with a length of 400mm, and extends approximately 100mm above the top of the protective cover. The outer diameter of the main head is 2-3mm larger than the diameter of the top beacon pole to which it is connected. The auxiliary head is made of 1Cr18Ni9Ti rust-proof and corrosion-resistant stainless steel, in a hemispherical arc shape, with a diameter of 12mm. Protective exterior construction of the bedrock leveling beacon involves embedding the beacon information in the walls of the beacon building. The beacon building protects the beacon itself, and a marble slab containing the beacon information, including its name, final borehole depth, construction unit, contractor, and completion date, is embedded on one side of the beacon building wall. Relative settlement observations of the bedrock beacon, protective pipe, and protective building are conducted using a differential pressure hydrostatic level. The differential pressure hydrostatic level sensor has a resolution of 0.01% fs and an accuracy of 0.05% fs, and features temperature compensation. Three sensors are installed on the main bedrock marker, the protective pipe, and the interior wall of the observation room, respectively. A solar panel is installed on the sun-facing exterior wall. A data acquisition terminal is mounted below the solar panel on the exterior wall. A communication antenna is fixed to the solar panel bracket. A water tank is installed on the interior wall, positioned higher than the other sensors. The differential pressure hydrostatic level sensor transmits monitoring data to a network server in real time via a communication network.

[0062] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The patent scope of the present invention should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention still fall within the patent scope of the present invention.

Claims

1. A method for constructing a kilometer-level bedrock leveling beacon to control borehole inclination, characterized in that, Includes the following steps: Step A: Leveling the foundation layer within the project area, vertically installing the drilling equipment, and securing the drilling tower; Step B: Use a large-diameter drill bit with light pressure and slow rotation to drill a reverse hole, while taking into account the lithological characteristics. The technique of inverted hole drilling is employed, combined with pressure and speed control, specifically including: Step B1: Select the appropriate drill bit type according to the lithology of the formation. In soft upper formations, use milling tooth drill bits; in hard formations, use insert tooth drill bits; in easily inclined formations, use roller cone drill bits with small offset, no gauge protection teeth, or many short teeth. Step B2: The drilling pressure is adjusted to achieve the breaking strength value of the rock being drilled, and is selected in combination with the equipment capacity and drill bit strength. 3kN / cm to 4kN / cm is used for drilling in medium to hard rock formations, and 1kN / cm to 3kN / cm is used for drilling in softer formations below medium to hard. Step B3: The linear velocity of the drill bit's outer edge rotation is 0.8 m / s to 1.5 m / s, decreasing to 0.6 m / s when encountering gravel or severely fractured strata; the drilling speed is 80 r / min to 145 r / min when the strata are intact, the hardness is low, the borehole is shallow, and the speed is 30 r / min to 60 r / min when encountering fractured strata. Step B4: The bottom pressure should not exceed two-thirds of the total weight of the drill collar. Use uniform drilling speed and light pressure with slow rotation. Control the verticality of the bedrock marker during the process. Drill to fresh, undisturbed bedrock, perform lithological analysis, and then continue drilling. Step C: Cementing protection is achieved using seamless steel pipe with threaded connections. The bottom is sealed with welded steel plates. Mud is injected between the protective pipe and the borehole wall. After the mud solidifies, the drill pipe is pulled out. This specifically includes: Step C1, Hole inclination: Use drill collars to apply pressure during drilling. The total mass of the drill collars should exceed the normal pressure value by 30%, and a stabilizer should be installed on the bottom drill collar. When encountering a soft-hard interface, use a smaller drill pressure to drill, and then increase the designed drill pressure to drill after passing through the interface. Step C2: Monitor borehole inclination. Monitor the borehole inclination every 50m of drilling. If the verticality exceeds the specified value, correct the borehole inclination. Step C3: Use seamless steel pipes for cementing protection, and connect the protective pipes with threaded connections; Step C4: Cut a slurry return hole at the bottom of the lowest casing. After the protective pipe is installed, lower the drill rod from inside the protective pipe to a distance above the bottom of the hole. Then, weld and fix the drill rod around the opening of the protective pipe with a steel plate. Step C5: Using vacuum wall protection technology, the wall protection slurry is pumped into the hole through the drill pipe. Clean water or slurry enters the gap between the protective pipe and the hole wall and returns to the ground. After the circulation is normal, the well-mixed cement slurry is pumped into the hole from the drill pipe using a mud pump until cement slurry returns from the hole opening. Step C6: Clean the drill pipe of any remaining cement slurry with clean water, let it stand for a period of time until the cement slurry solidifies, and then remove the drill pipe. Step D: Drill the bottom hole using a small-diameter drill bit with varying drill pressure and drilling speed, and measure relevant parameters after well completion; Step E: Install the steel ring tray at the bottom of the drill hole; Step F, Installation of kilometer-level bedrock marker poles: Before lowering the pipe, the hole depth is corrected, and the pipe lowering work is completed in one go using the wire rope lifting method. To ensure the verticality of the marker pole, a straightener is added. After lowering the pipe, cement grout is injected into the marker pole, and the pressure drop method using a check valve is used to fix the marker. Step G: Installation of the main and auxiliary benchmarks for the bedrock leveling system and construction of protective exterior decorations; embedding the benchmark information in the walls of the benchmark building; using a differential pressure hydrostatic level to observe the relative settlement of the bedrock benchmark, retaining pipe, and protective building.

2. The method for constructing a kilometer-level bedrock leveling beacon to control borehole inclination according to claim 1, characterized in that, Step A specifically includes: Step A1: The total area of ​​the construction site shall not be less than 25m×25m. The site shall be leveled. Loose strata shall be poured with cement and then drill tower timber shall be added. Drill tower timber shall be installed directly on hard strata. Step A2: Place the drilling rig on the ground beam, aligning the center of the turntable with the center of the drilling tower's overhead beam. Fix and level the drilling rig and the ground beam, ensuring that the overhead crane, pulley, and turntable center are in a straight line. Step A3: After the drilling rig is erected, it should be secured on all four sides with windproof ropes or steel wires, and the angle with the ground should not exceed 45 degrees. The ends of the ropes should be fastened with clips.

3. The method for constructing a kilometer-level bedrock leveling beacon to control borehole inclination according to claim 1, characterized in that, After the drill bit in step D contacts the bottom of the hole, it is first broken in for more than 0.5 hours at low drilling pressure and low rotation speed to form the bottom shape. Then, the drilling pressure and rotation speed are gradually increased to normal parameters. Finally, the relevant parameters of the well are measured, including temperature and well inclination.

4. The method for constructing a kilometer-level bedrock leveling beacon to control borehole inclination according to claim 1, characterized in that, The steel ring-shaped tray mentioned in step E is used to increase the contact area between the marker and the bedrock, and a certain amount of cement is poured in to solidify it with the rock, ensuring stability.

5. The method for constructing a kilometer-level bedrock leveling beacon to control borehole inclination according to claim 1, characterized in that, Step F specifically includes: Step F1: Before lowering the pipe, perform hole depth correction and check the sequence and code of the marker pipes to ensure that the cumulative length of the marker poles matches the actual marking depth, and the error shall not exceed 1m; Step F2: After the bottom of the marker pole is inserted into the hole of the steel support plate, the marker pole is installed. The lowering of the marker pole is completed in one go using the wire rope lifting method. The screws between the pipes are tightened to prevent them from falling off. Step F3: When lowering the marker, add a ball bearing stabilizer every 8-10m to ensure the verticality of the marker. Step F4: After the marker is in place, pour a measured amount of cement grout into the marker. Step F5: The benchmark is fixed by pumping pressure drop using a check valve. Before fixing the benchmark, the inner and outer sleeve sealing devices are installed at the two-stage sleeve joint to ensure a reliable seal in the tubular annular gap of the overlapping part of the two-stage sleeves.

6. The method for constructing a kilometer-level bedrock leveling beacon to control borehole inclination according to claim 1, characterized in that, In step G, the main marker head is installed at the top of the marker pole, and the secondary marker head is installed on one side of the protective pipe and integrated with the protective pipe; a marker house is built to protect the marker body, and a marble slab with bedrock marker information is inlaid on one side of the marker house wall; multiple differential pressure static leveling sensors are installed, and monitoring data is transmitted to the network server in real time through a communication network.