Self-drilling aerated lightweight soil-cement MJS apparatus and construction method therefor

Abstract

Disclosed are a self-drilling aerated lightweight soil-cement MJS apparatus and a construction method therefor. The self-drilling aerated soil-cement MJS apparatus comprises a porous pipe, an integrated apparatus, a reamer head, a pressure monitoring system, a quality measurement instrument, and a console. During foundation reinforcement, the reamer head cuts a soil mass and then the soil mass is transported, by means of a mud discharge pipe, to a waste liquid tank. The quality measurement instrument performs measurement on the extracted soil mass, then performs calculation, and cement of an equal mass is injected. Meanwhile, a pressure sensor uploads detected water and soil pressure data, and the degree of opening and closing of a mud discharge outlet is controlled, so that safe construction having equivalent self-weight stress from stratum in a reinforced region and balanced water soil pressure is achieved, adverse effects caused by settlement are reduced to a certain extent, and safe and efficient foundation reinforcement construction is achieved.

Description

A self-drilling aerated lightweight cement soil MJS device and its construction method Technical Field

[0001] The present invention relates to the technical field of foundation reinforcement, and in particular to a self-drilling aerated lightweight cement soil MJS device and a construction method thereof. Background Art

[0002] As underground space continues to develop in depth and in three dimensions, foundation reinforcement technology, an important technical means to ensure the smooth development of underground projects, has also been continuously improved, and higher requirements have been put forward for the environmental disturbance effect and reinforcement effect of foundation reinforcement.

[0003] High-pressure jet grouting is a common method for foundation reinforcement. On the one hand, high-pressure rotary jetting causes cement slurry to spread throughout the cracks in the ground, potentially contaminating the soil on a large scale. On the other hand, high-pressure jet grouting generates excess pore water pressure in the surrounding area during construction, which has a certain squeezing effect on the soil, causing surface soil uplift and lateral displacement. Furthermore, after high-pressure jet grouting reinforcement, soil particles mix with cement, and the density of the cement-soil in the reinforced area is greater than that of the original soil. This will generate additional stress, causing foundation settlement, leading to tilting and deformation of the foundations of adjacent structures, and even structural damage.

[0004] Therefore, in order to reduce and eliminate the hazards of soil settlement and deformation caused by traditional foundation reinforcement methods and improve the efficiency of foundation reinforcement construction, a self-drilling aerated lightweight cement soil MJS device is urgently needed.

[0005] Summary of the Invention

[0006] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a self-drilling aerated lightweight cement soil MJS device and a construction method thereof.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A self-drilling aerated lightweight cement soil MJS device, comprising a porous pipe, an integrated device, a reamer head, a pressure monitoring system, a mass measuring instrument and a control console; the pressure monitoring system comprises a pressure sensor and a collector;

[0009] The porous tube, integrated device and reamer head are connected from top to bottom to form the drill pipe body;

[0010] The porous pipe integrates a mud discharge pipe, a high-pressure cement slurry pipe, a spare pipe, a negative pressure air pipe, a reserve air pipe, a negative pressure water pipe, a hydraulic pipe, a pressure sensor line pipe, a pressure water pipe, a power line pipe and a main air pipe;

[0011] The outer side of the cylinder wall of the integrated device is provided with a high-pressure water spray port, a mud discharge port, a pressure sensor and a plurality of high-pressure grouting ports from top to bottom; a mud discharge bin is also provided inside;

[0012] The reamer head is located at the bottom of the integrated device and is connected to the mud discharge pipe through the mud discharge bin inside the integrated device; a pressure water outlet is provided on the top of the reamer head; a pressure water outlet is provided on the top of the reamer head;

[0013] The integrated device is provided with a motor device for driving the reamer head to rotate and cut the soil independently, so as to avoid the disturbance of the surrounding soil by the overall rotation of the drill rod when the drill rod is lifted;

[0014] Each of the negative pressure air pipe, the reserve air pipe and the negative pressure water pipe forms two branches with pressure control valves in the integrated device, which are respectively connected to the mud discharge port and the mud discharge bin to assist in mud discharge and excavation; the mud discharge port and the mud discharge bin are both connected to the mud discharge pipe for mud discharge and excavation;

[0015] The hydraulic pipe forms three branches with pressure control valves in the integrated device, which are connected to the mud discharge port, mud discharge bin and motor device respectively;

[0016] The pressure water pipe forms two branches with pressure control valves in the integrated device, which are connected to the high-pressure water spray port on the cylinder wall of the integrated device and the pressure water outlet on the top of the reamer head respectively;

[0017] The upper end of the main air pipe is connected to the air compressor;

[0018] The high-pressure cement slurry pipe is divided into an aerated cement slurry pipe and a lightweight cement slurry pipe, which are connected to the high-pressure grouting port of the integrated device;

[0019] The power line pipe is used for power supply; the high-pressure water jet nozzle cuts the soil through high-pressure water; the mud discharge port is used to discharge the soil-water mixture formed after high-pressure water cutting, as well as the excess cement slurry after high-pressure grouting;

[0020] The mass measuring instrument is arranged in the waste liquid tank, measures the mass of the soil-water mixture pumped into the waste liquid tank through the mud discharge pipe, and transmits the measured data to the control console;

[0021] The pressure sensor is connected to the collector via a wire in the pressure sensor circuit tube, and the collector is connected to a control console; the control console is used to regulate the coordinated control operations of various pressure control valves and control the motor.

[0022] Furthermore, the upper end of the aerated cement slurry pipe is connected to the cement slurry bin, and the cement slurry used is mixed with a quick-setting agent. The aerated cement slurry pipe is connected to the main air pipe through several branch air pipes equipped with pressure control valves in the integrated device. After the aerated cement slurry pipe is connected to the branch air pipe and gas is injected, it penetrates into the main air pipe at the high-pressure grouting port to form a coaxial double-layer pipe structure connected to the high-pressure grouting port.

[0023] Furthermore, the pressure control valve is connected to the console through a wire in the pressure sensor line pipe, and adjusts the air pressure in the branch air pipe according to the water and soil pressure data collected by the pressure sensor to control the gas to enter the cement slurry in the high-pressure cement slurry pipe.

[0024] Furthermore, the upper end of the lightweight cement slurry pipe is connected to a cement slurry bin, and the lightweight cement slurry in the cement slurry bin contains a foaming agent, which is divided into a first type of foaming agent and a second type of foaming agent;

[0025] The first type of foaming agent is a surfactant foaming agent,

[0026] The second type of foaming agent is composed of aluminum powder, iron powder, opening powder and air-entraining agent, mixed in a ratio of 9:9:1:1; the foaming agent is used to produce closed bubbles in cement slurry; the air-entraining agent increases the number of bubbles and makes them uniform; the second type of foaming agent can also be adjusted in proportion based on indoor tests and field tests to adapt to more engineering scenarios.

[0027] Furthermore, the amount of the foaming agent added to the cement slurry bin is adjusted in real time based on the water and soil pressure data collected by the pressure sensor, requiring the volume of the lightweight cement soil to be the same as the volume of the discharged soil-water mixture;

[0028] Furthermore, the reamer head consists of a reamer bit and a reamer ring; the reamer bit and the reamer ring are fixedly connected, and the reamer blade with serrations is fixedly connected to the reamer bit.

[0029] Furthermore, the mud discharge pipe discharges mud and excavates the earth through negative pressure; the prepared air pipe contains pressurized gas, which is used to pressurize and clean the hole when the pipeline is blocked; the upper end of the pressure water pipe is connected to a pressure water tank.

[0030] Furthermore, the high-pressure grouting ports are arranged in pairs, and at least one pair of high-pressure grouting ports is arranged on the integrated device; the diameter of the branch air pipe is determined by the gas flux to be injected into the high-pressure cement slurry pipe; the diameter of the high-pressure cement slurry pipe in the coaxial double-layer pipe structure connected to the high-pressure grouting ports is smaller than the main air pipe.

[0031] Furthermore, the mud discharge port is separated from the high-pressure grouting port to prevent the mud discharge port from discharging unsolidified cement slurry in the reinforcement area; the maximum outer diameter of the reamer head should be larger than the outer diameter of the porous pipe and the integrated device.

[0032] On the other hand, the present invention also provides a construction method for a self-drilling aerated lightweight cement soil MJS device, which comprises the following steps:

[0033] S1. Measurement and positioning: setting up groundwater level and land subsidence monitoring points in the area to be reinforced to monitor the groundwater level and land subsidence in real time;

[0034] S2. After the various pipelines of the self-drilling aerated cement soil MJS device are connected, the control console controls the motor device to drive the reamer head to rotate at high speed, so that the reamer drill bit and the reamer blade thereon cut the soil; the cut soil and pressurized water sprayed from the pressure outlet form a soil-water mixture, which is discharged through the mud discharge bin and mud discharge pipe; according to the groundwater level change monitoring data, pressurized water is injected to replenish the groundwater to maintain a constant groundwater level;

[0035] S3. After drilling to the designed depth, turn off the motor device, pressure water outlet, and mud discharge bin, and stop drilling operation;

[0036] S4. After high-pressure water is ejected from the high-pressure water jet outlet to cut the soil, high-pressure cement slurry is ejected from the high-pressure grouting outlet for grouting reinforcement. The drill pipe is rotated and lifted, and the high-pressure water jet outlet and high-pressure grouting outlet respectively continue to perform high-pressure water cutting and high-pressure grouting reinforcement operations. If the aerated cement slurry pipe needs to be aerated, the pressure control valve is controlled by the console to allow the pressurized gas in the branch air pipe to be injected into the cement slurry in the high-pressure cement slurry pipe, forming aerated cement slurry with evenly distributed bubbles.

[0037] During the high-pressure water cutting process, the control console obtains water and soil pressure data and the mass of the soil-water mixture through pressure sensors and mass measuring instruments. The console adjusts the opening and closing degree of the mud discharge valve to control the discharge of high-pressure cement slurry and high-pressure water, ensuring that the water and soil pressure in the reinforced area remains constant.

[0038] S5. After the soil grouting reinforcement is completed, the self-drilling aerated cement soil MJS device is turned off and the connections of each pipeline of the self-drilling aerated cement soil MJS device are disconnected;

[0039] S6. Repeat S1-S5 until all grouting reinforcement construction in the area to be reinforced is completed.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present invention provides two high-pressure cement slurry pipes. When using aerated cement slurry pipes, branch pipes branch out from the main pipe to continuously add gas to the high-pressure cement slurry pipes. This can quickly encapsulate the gas to form closed bubbles, ensuring that the gas is evenly distributed in the cement liquid and that the strength at different locations in the reinforced area is essentially the same, avoiding the occurrence of uneven bubbles that may cause breakage. This effectively prevents ground subsidence caused by additional stress generated by the increased density of the reinforced area after grouting, as well as potential damage to surrounding structures. It fundamentally reduces and eliminates the hazards of soil settlement and deformation caused by traditional foundation reinforcement methods, making it particularly suitable for construction in densely built areas.

[0042] The aerated cement slurry pipe and the main gas pipe form a coaxial double-layer casing structure, which wraps high-pressure gas around the high-pressure sprayed cement, standardizes the cement spraying range, and makes the foundation reinforced into a regular shape, thereby improving its reliability and controllability.

[0043] When using lightweight cement slurry pipes, foamed lightweight cement is used for reinforcement. The cement slurry and the foaming agent are fully and evenly mixed in the slurry bin, so that the foaming agent has sufficient time to foam in the cement slurry to form foamed lightweight cement slurry with stable and uniform bubbles, ensuring the stable quality of the foamed lightweight cement slurry.

[0044] The present invention provides a reamer head connected to the integrated device. The reamer blade on the reamer head is a serrated reamer blade. The cut soil is mixed with water and then extracted to perform drilling work, and then grouting reinforcement can be directly performed without the need to use other hole-guiding equipment, which greatly improves the efficiency of foundation reinforcement construction and achieves the effect of simplifying the process and shortening the construction period.

[0045] A motor device is provided in the integrated device of the present invention, and the motor device drives the reamer head to operate independently when drilling; the soil is excavated by mixing soil and water, and part of the mud formed by the soil-water mixture remains in the borehole, which plays a role in protecting the wall and can also effectively reduce the frictional resistance between the drill rod surface and the surrounding soil, further reducing the disturbance of the surrounding soil caused by the construction, preventing the adverse effects of the soil squeezing effect, achieving micro-disturbance construction, and improving the safety and reliability of construction.

[0046] The present invention provides a pressure water outlet, and injects pressurized water when cutting the soil. On the one hand, the soil cut from the drilling hole and the water can form a soil-water mixture, which is convenient for discharging the cut soil. On the other hand, groundwater is recharged in real time according to the changes in the groundwater level, ensuring that the groundwater level remains unchanged and avoiding the problem of ground subsidence caused by precipitation.

[0047] In the present invention, the pressure monitoring system, mass measuring instrument and control console work together, the water and soil pressure of the site during construction is monitored by the pressure sensor, the mass of the discharged soil is monitored by the mass measuring instrument, and the mass of the injected cement is calculated so that the mass of the injected cement is balanced with the amount of discharged soil. The control console adjusts the opening and closing degree of the mud outlet valve to regulate the mass of the discharged soil-water mixed soil, effectively controls the amount of excavated soil in the borehole, ensures that the self-weight stress of the stratum in the reinforced area is equivalent to the water and soil pressure, and achieves the purpose of equivalence between the self-weight stress of the stratum in the reinforced area and the self-weight stress of the stratum in the original site, effectively solving the problem of ground subsidence caused by the increase of the self-weight stress in the reinforced area.

[0048] The control console in the present invention is connected to the porous pipe, the integrated device, the pressure monitoring system and the quality measuring instrument, and regulates the drilling operation, the high-pressure water soil cutting operation, the high-pressure grouting reinforcement operation, the mud discharge operation and the coordinated control operation of each pressure control valve of the self-drilling aerated cement soil MJS device. It adjusts and controls in real time according to monitoring data such as the groundwater level, the ground subsidence and the water and soil pressure in the stratum, so as to ensure that the water and soil pressure in the reinforcement area remains constant and the self-weight stress of the stratum before and after the construction of the reinforcement area is equivalent. It can effectively reduce the adverse effects of the grouting project on the surrounding environment, greatly improve the grouting efficiency and reinforcement effect, and conform to the concept of smart engineering construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG1 is a side view of a self-drilling aerated cement soil MJS device according to the present invention;

[0050] FIG2 is a cross-sectional view taken along line AA of FIG1 ;

[0051] FIG3 is a schematic diagram of a grouting conduit unit.

[0052] In the figure, porous pipe 1, mud discharge pipe 1-1, high-pressure cement slurry pipe 1-2, spare pipe 1-3, negative pressure air pipe 1-4, reserve air pipe 1-5, negative pressure water pipe 1-6, hydraulic pipe 1-7, pressure sensor wire pipe 1-8, pressure water pipe 1-9, power wire pipe 1-10, main air pipe 1-11, branch air pipe 1-11-1, integrated device 2, high-pressure water spray port 3, mud discharge port 4, high-pressure grouting port 5, pressure sensor 6, reamer head 7, reamer drill bit 7-1, reamer blade 7-1-1, reamer ring 7-2, pressure control valve 8. DETAILED DESCRIPTION

[0053] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0054] As shown in FIG1 , an embodiment of the present invention provides a self-drilling aerated lightweight cement soil MJS device, comprising a porous pipe 1, an integrated device 2, a reamer head 7, a pressure monitoring system, a mass measuring instrument, and a control console; the pressure monitoring system comprises a pressure sensor 6 and a collector;

[0055] The porous pipe 1, the integrated device 2 and the reamer head 7 are connected from top to bottom to form the drill pipe body;

[0056] As shown in FIG2 , the porous pipe 1 integrates a mud discharge pipe 1-1, a high-pressure cement slurry pipe 1-2, a spare pipe 1-3, a negative pressure air pipe 1-4, a reserve air pipe 1-5, a negative pressure water pipe 1-6, a hydraulic pipe 1-7, a pressure sensor line pipe 1-8, a pressure water pipe 1-9, a power line pipe 1-10 and a main air pipe 1-11;

[0057] The outer side of the cylinder wall of the integrated device 2 is provided with a high-pressure water spray port 3, a mud discharge port 4, a pressure sensor 6 and a high-pressure grouting port 5 from top to bottom;

[0058] The reamer head 7 is composed of a reamer drill bit 7-1 and a reamer ring 7-2; the reamer drill bit 7-1 and the reamer ring 7-2 are fixedly connected, and the reamer blade 7-1-1 with serrations is fixedly connected to the reamer drill bit 7-1; the reamer head 7 is located at the bottom of the integrated device 2 and is connected to the mud discharge pipe 1-1 through the mud discharge bin inside the integrated device 2;

[0059] A motor device is provided near the bottom area of ​​the integrated device 2 to drive the reamer head 7 to rotate and cut the soil independently, so as to avoid the disturbance of the surrounding soil by the rotation of the drill rod as a whole;

[0060] The main air pipe 1-11 is connected to the high-pressure grouting port, and the upper end of the main air pipe 1-11 is connected to the air compressor; when spraying concrete, the main air pipe 1-11 is required to provide pressurized air. The spare pipe 1-3 is used to connect other functional pipes in case of damage.

[0061] The negative pressure air pipe 1-4, the reserve air pipe 1-5, and the negative pressure water pipe 1-6 all form two branches with pressure control valves in the integrated device 2, which are respectively connected to the mud discharge port 4 and the mud discharge bin to assist in mud discharge and excavation; the mud discharge port 4 and the mud discharge bin are both connected to the mud discharge pipe 1-1 for mud discharge and excavation;

[0062] The hydraulic pipes 1-7 form three branches with pressure control valves in the integrated device 2, which are connected to the mud discharge port 4, the mud discharge bin and the motor device respectively;

[0063] The penstocks 1-9 form two branches within the integrated device 2, each equipped with a pressure control valve, connecting the high-pressure water jet port 3 on the wall of the integrated device 2 and the pressure water outlet on the top of the reamer head 7. The pressure water outlet on the top of the reamer head 7 sprays pressurized water, which, on the one hand, can be used to reduce drag and cool the reamer head 7 when cutting soil, while facilitating the discharge of the soil-water mixture from the mud discharge port 4. On the other hand, it can be used to balance the amount of groundwater discharged through the mud discharge port 4, thereby ensuring that the groundwater level remains unchanged and preventing ground subsidence caused by the decline of groundwater.

[0064] The high-pressure water jet 3 cuts the soil with high-pressure water; the mud discharge port 4 is used to discharge the soil-water mixture formed after high-pressure water cutting, as well as the excess cement slurry after high-pressure grouting;

[0065] The high-pressure grouting ports 5 are arranged in pairs, and each high-pressure grouting port 5 is equipped with a grouting conduit unit; the grouting conduit unit is composed of a high-pressure cement slurry pipe 1-2, a main air pipe 1-11, a branch air pipe 1-11-1 and a pressure control valve 8; the branch air pipe 1-11-1 branches out from the main air pipe 1-11 in the integrated device 2 and is connected to the high-pressure cement slurry pipe 1-2 through the pressure control valve 8; the pressure control valve 8 is used to control the pressure of the gas injected into the high-pressure cement slurry pipe 1-2 from the branch air pipe 1-11-1. force; after the high-pressure cement slurry pipe 1-2 is connected to the branch air pipe 1-11-1 and gas is injected, it penetrates into the main air pipe 1-11 near the high-pressure grouting port 5 to form a coaxial double-layer pipe structure connected to the high-pressure grouting port 5; the pressure control valve 8 is connected to the console through the wire in the pressure sensor line pipe 1-8, and adjusts the air pressure in the branch air pipe 1-11-1 according to the water and soil pressure data, and controls the gas to enter the cement slurry of the high-pressure cement slurry pipe 1-2, so that the bubbles in the soil in the reinforcement area are evenly distributed and the pore content is stable;

[0066] The pressure sensor 6 is connected to the data acquisition instrument via the wires in the pressure sensor line pipes 1-8, and transmits the real-time collected water and soil pressure data to the data acquisition instrument; the data acquisition instrument is connected to the control console; if the data acquisition instrument detects abnormal water and soil pressure, the control console will adjust the opening and closing degree of the mud discharge port 4 valve to control the discharge of high-pressure cement slurry and high-pressure water, ensuring that the water and soil pressure in the reinforced area remains constant;

[0067] The mass measuring instrument is set in the waste liquid tank to measure the mass of the soil-water mixture pumped into the waste liquid tank through the mud discharge pipe 1-1, and transmits the measured data to the control console, which adjusts and controls the mass of the cement slurry injected into the reinforcement area so that the self-weight stress of the stratum before and after construction in the reinforcement area is equivalent.

[0068] As shown in Figure 3, the multiple porous pipes 1 can be extended by bolt connection; the mud discharge pipe 1-1 discharges mud and excavates the earth through negative pressure; the upper end of the high-pressure cement slurry pipe 1-2 is connected to the cement slurry bin; the cement slurry of the high-pressure cement slurry pipe 1-2 should be mixed with a quick-setting agent, and after the gas is injected through the branch air pipe 1-11-1, it can quickly wrap the gas to form a closed bubble; the prepared air pipe 1-5 contains pressurized gas, which can be used for pressurized hole cleaning when the pipeline is blocked; the upper end of the pressure water pipe 1-9 is connected to the pressure water tank; the upper end of the main air pipe 1-11 is connected to the air compressor; the pressure control valve, pressure sensor 6, and pressure control valve 8 of the negative pressure air pipe 1-4, the prepared air pipe 1-5, the negative pressure water pipe 1-6, the hydraulic pipe 1-7 and the pressure water pipe 1-9 branch are powered by the power cord in the power line pipe 1-10, and are all connected to the console through the wire in the pressure sensor line pipe 1-8.

[0069] At least one pair of high-pressure grouting ports 5 is provided on the integrated device 2; the diameter of the branch air pipe 1-11-1 is determined by the gas flux to be injected into the high-pressure cement slurry pipe 1-2; the diameter of the high-pressure cement slurry pipe 1-2 in the coaxial double-layer pipe structure connected to the high-pressure grouting port 5 is smaller than that of the main air pipe 1-11.

[0070] The motor device is connected to the branch of the hydraulic pipe 1-7 and the power line in the power line pipe 1-10, and the control wire of the motor device passes through the pressure sensor line pipe 1-8 and is connected to the console.

[0071] The mud discharge port 4 is separated from the high-pressure grouting port 5 to prevent the mud discharge port 4 from discharging the unsolidified cement slurry in the reinforcement area, causing waste of cement slurry, affecting the reinforcement effect, and even clogging the pipeline; the maximum outer diameter of the reamer head 7 should be larger than the outer diameter of the porous pipe 1 and the integrated device 2.

[0072] The control console is connected to the porous pipe 1, the integrated device 2, the pressure monitoring system and the quality measuring instrument, and regulates the drilling operation, high-pressure water soil cutting operation, high-pressure grouting reinforcement operation, mud discharge operation and the coordinated control operation of each pressure control valve of the self-drilling aerated cement soil MJS device.

[0073] On the other hand, an embodiment of the present invention provides a construction method for a self-drilling aerated lightweight cement soil MJS device, the method comprising the following steps:

[0074] Step 1: Measurement and positioning: Set up groundwater level and ground subsidence monitoring points in the area to be reinforced to monitor the groundwater level and ground subsidence in real time;

[0075] Step 2: After all the pipes of the self-drilling aerated cement soil MJS device are connected, the drilling system of the self-drilling aerated cement soil MJS device is started through the control console to perform the drilling operation: the motor device drives the reamer head 7 to rotate at high speed, and the reamer drill bit 7-1 and the reamer blade 7-1-1 thereon cut the soil; the cut soil and the pressurized water sprayed from the pressure outlet form a soil-water mixture, which is discharged through the mud discharge bin and mud discharge pipe 1-1; according to the groundwater level change monitoring data, the groundwater is replenished by injecting pressurized water to maintain the groundwater level unchanged;

[0076] Step 3: After drilling to the designed depth, turn off the motor device, pressure water outlet, and mud discharge bin, and stop drilling;

[0077] Step 4: Start the high-pressure water cutting and high-pressure cement slurry grouting reinforcement systems of the self-drilling aerated cement soil MJS device through the control console: After high-pressure water is ejected from the high-pressure water jet port 3 to cut the soil, high-pressure cement slurry is ejected from the high-pressure grouting port 5 to perform grouting reinforcement; the drill rod is rotated and lifted at a certain speed, and the high-pressure water jet port 3 and high-pressure grouting port 5 continue to perform high-pressure water cutting and high-pressure grouting reinforcement operations respectively;

[0078] During the high-pressure water cutting process in step 4, the pressure sensor 6 transmits the water and soil pressure data to the control console via the data acquisition instrument. The console adjusts the opening and closing degree of the mud discharge port 4 valve to control the discharge of high-pressure cement slurry and high-pressure water to ensure that the water and soil pressure in the reinforced area remains constant.

[0079] During the high-pressure grouting process in step 4, the control console controls the pressure control valve 8 so that the pressurized gas in the branch gas pipe 1-11-1 is injected into the cement slurry in the high-pressure cement slurry pipe 1-2, forming aerated cement slurry with evenly distributed bubbles. The slurry is then ejected from the high-pressure grouting port 5 for grouting reinforcement. The mass of the soil-water mixture is measured by a mass measuring instrument, and the measured data is transmitted to the control console. The control console adjusts and controls the mass of the cement slurry injected into the reinforcement area so that the self-weight stress of the stratum before and after construction in the reinforcement area is equivalent.

[0080] Step 5: After the soil grouting reinforcement is completed, the self-drilling aerated cement soil MJS device is turned off and the connections of each pipeline of the self-drilling aerated cement soil MJS device are disconnected;

[0081] Step 6: Repeat steps 1-5 until all grouting reinforcement construction in the area to be reinforced is completed.

[0082] In steps 2-4, for soil that is prone to collapse after drilling, an outer sleeve can be set within the porous tube to prevent the collapsed soil from affecting the operation of the reamer head 7 and the integrated device 2; the outer sleeve should be consistent with the upward lifting speed of the drill rod.

[0083] In step 4, the quality of the cement slurry should be tested to ensure that it meets the grouting reinforcement requirements; the drill rod is rotated and lifted by the top power device, and the rotation and lifting speed should ensure that the mud outlet 4 can extract the mud containing a large amount of soil, and ensure that the grouting aerated cement soil can fully replace the original soil in the reinforcement area, meet the equivalence of the stratum gravity before and after the reinforcement construction, and improve the soil strength of the reinforcement area.

[0084] In step 4, the pressure gas in the cement slurry injected into the high-pressure cement slurry pipe 1-2 by the branch air pipe 1-11-1 should be adjusted in real time according to the grouting reinforcement depth to ensure that the bubbles in the reinforced soil at different depths are evenly distributed and the pore content is stable; the mass of the cement slurry injected into the reinforcement area should be equal to the mass of the natural soil discharged from the mud discharge pipe 1-1; the mass of the natural soil discharged from the mud discharge pipe 1-1 is calculated based on the dry mass of the soil in the soil-water mixture and the density and moisture content of the natural soil obtained from geological surveys; the natural soil discharged from the mud discharge pipe 1-1 consists of two parts: soil cut by drilling and soil cut by high-pressure water; in step 6, the quality of the grouting reinforced soil should be tested by the method specified in the specification.

[0085] Example 2:

[0086] A self-drilling MJS device for lightweight cement soil reinforcement includes a porous pipe 1, an integrated device 2, a reamer head 7, a pressure monitoring system, a mass measuring instrument, and a control console; the pressure monitoring system includes a pressure sensor 6 and a collector;

[0087] The porous pipe 1, the integrated device 2 and the reamer head 7 are connected from top to bottom to form the drill pipe body;

[0088] The porous pipe 1 integrates a porous pipe 1, a mud discharge pipe 1-1, a high-pressure cement slurry pipe 1-2, a spare cement slurry pipe 1-3, a negative pressure air pipe 1-4, a reserve air pipe 1-5, a negative pressure water pipe 1-6, a hydraulic pipe 1-7, a pressure sensor line pipe 1-8, a pressure water pipe 1-9, a power line pipe 1-10, and a main air pipe 1-11; the high-pressure cement slurry pipe in this embodiment is a lightweight cement slurry pipe, which is connected to the high-pressure grouting port of the integrated device;

[0089] The integrated device 2 is a sleeve-type integrated device, which is sleeved on the lower part of the porous pipe 1. The wall of the pipe is provided with a high-pressure water spray port 3, a mud discharge port 4, a high-pressure grouting port 5 and a pressure sensor 6 from top to bottom;

[0090] The reamer head 7 is composed of a reamer drill bit 7-1 and a reamer ring 7-2; the reamer drill bit 7-1 and the reamer ring 7-2 are fixedly connected, and the reamer blade 7-1-1 with serrations is fixedly connected to the reamer drill bit 7-1; the reamer head 7 is located at the bottom of the integrated device 2 and is connected to the mud discharge pipe 1-1 through the mud discharge bin inside the integrated device 2;

[0091] A motor device is provided in the integrated device 2 near the reamer head 7, which is used to drive the reamer head 7 to rotate and cut the soil alone, so as to avoid the disturbance of the surrounding soil by the rotation of the drill rod as a whole;

[0092] The main air pipe 1-11 is connected to the high-pressure grouting port, and the upper end of the main air pipe 1-11 is connected to the air compressor; when spraying concrete, the main air pipe 1-11 is required to provide pressurized air. The spare pipe 1-3 is used to connect other functional pipes in case of damage.

[0093] The negative pressure air pipe 1-4, the reserve air pipe 1-5, and the negative pressure water pipe 1-6 all form two branches with pressure control valves in the integrated device 2, which are respectively connected to the mud discharge port 4 and the mud discharge bin to assist in mud discharge and excavation; the mud discharge port 4 and the mud discharge bin are both connected to the mud discharge pipe 1-1 for mud discharge and excavation;

[0094] The hydraulic pipes 1-7 form three branches with pressure control valves in the integrated device 2, which are connected to the mud discharge port 4, the mud discharge bin and the motor device respectively;

[0095] The penstocks 1-9 form two branches within the integrated device 2, each equipped with a pressure control valve, connecting the high-pressure water jet port 3 on the wall of the integrated device 2 and the pressure water outlet on the top of the reamer head 7. The pressure water outlet on the top of the reamer head 7 sprays pressurized water, which, on the one hand, can be used to reduce drag and cool the reamer head 7 when cutting soil, while facilitating the discharge of the soil-water mixture from the mud discharge port 4. On the other hand, it can be used to balance the amount of groundwater discharged through the mud discharge port 4, thereby ensuring that the groundwater level remains unchanged and preventing ground subsidence caused by the decline of groundwater.

[0096] The high-pressure water jet port 3 uses high-pressure water to cut the soil; the mud discharge port 4 is used to discharge the soil-water mixture formed after high-pressure water cutting, as well as the excess cement slurry after high-pressure grouting; the high-pressure grouting port 5 uses high-pressure cement slurry to further cut the soil and reinforce it;

[0097] The pressure sensor 6 is connected to the collector through the wires in the pressure sensor line pipe 1-8, and transmits the real-time collected water and soil pressure data to the collector; the collector is connected to the control console; if the collector detects abnormal water and soil pressure, the control console will adjust the opening and closing degree of the mud outlet 4 valve to control the discharge of high-pressure cement slurry and high-pressure water, ensuring that the water and soil pressure in the reinforced area remains constant;

[0098] The mass measuring instrument is set in the waste liquid tank to measure the mass of the soil-water mixture pumped into the waste liquid tank through the mud discharge pipe 1-1, and transmits the measured data to the control console, which adjusts and controls the mass of the cement slurry injected into the reinforcement area so that the self-weight stress of the stratum before and after construction in the reinforcement area is equivalent.

[0099] Furthermore, the multiple porous pipes 1 can be extended by bolt connection; the mud discharge pipe 1-1 discharges mud and excavates the earth through negative pressure; the upper end of the high-pressure cement slurry pipe 1-2 is connected to the cement slurry bin; the prepared air pipe 1-5 contains pressurized gas, which can be used for pressurized hole cleaning when the pipeline is blocked; the upper end of the pressure water pipe 1-9 is connected to the pressure water tank; the upper end of the main air pipe 1-11 is connected to the air compressor; the spare cement slurry pipe 1-3, the negative pressure air pipe 1-4, the prepared air pipe 1-5, the negative pressure water pipe 1-6, the hydraulic pipe 1-7 and the pressure control valve of the pressure water pipe 1-9 branch, and the pressure sensor 6 are powered by the power cord in the power line pipe 1-10, and are all connected to the console through the wire in the pressure sensor line pipe 1-8.

[0100] The motor device is connected to the branch of the hydraulic pipe 1-7 and the power line in the power line pipe 1-10, and the control wire of the motor device passes through the pressure sensor line pipe 1-8 and is connected to the console.

[0101] Furthermore, the foaming agent is divided into a first type of foaming agent and a second type of foaming agent;

[0102] The first type of foaming agent is a surfactant foaming agent. The bubbles produced by the foaming agent should meet the following requirements:

[0103] (1) The bubbles should be uniform and dense, with a bubble density of 48kg / m3 to 52kg / m3;

[0104] (2) The settling height of a standard bubble column in one hour is no more than 6 mm;

[0105] (3) The water secretion volume of the standard bubble column in 1 hour is not more than 20 ml;

[0106] (4) The increase in wet bulk density determined by the defoaming test should not exceed 10%. (Excerpt from the Technical Specifications for Bubble Mixed Lightweight Soil Filling Engineering) (Directly supplied by the surfactant foaming agent manufacturer);

[0107] The second type of foaming agent is composed of aluminum powder, iron powder, opening powder and a small amount of air-entraining agent, mixed in a ratio of 9:9:1:1; the foaming agent is used to produce closed bubbles in cement slurry; the air-entraining agent increases the number of bubbles and makes them uniform; the second type of foaming agent can also be adjusted in proportion based on indoor and field tests to adapt to more engineering scenarios.

[0108] The amount of the foaming agent added to the cement slurry bin is adjusted in real time according to the water and soil pressure data collected by the pressure sensor 6, requiring the volume of the lightweight cement soil to be the same as the volume of the discharged soil-water mixture;

[0109] Furthermore, the control console is connected to the porous pipe 1, the integrated device 2, the pressure monitoring system and the quality measuring instrument to regulate the drilling operation, high-pressure water soil cutting operation, high-pressure grouting reinforcement operation, mud discharge operation and coordinated control operation of each pressure control valve of the spiral cutter suction MJS device for lightweight cement soil reinforcement.

[0110] The mud discharge port 4 is separated from the high-pressure grouting port 5 to prevent the mud discharge port 4 from discharging the unsolidified cement slurry in the reinforcement area, causing waste of cement slurry, affecting the reinforcement effect, and even clogging the pipeline; the maximum outer diameter of the reamer head 7 should be larger than the outer diameter of the porous pipe 1 and the integrated device 2.

[0111] On the other hand, an embodiment of the present invention provides a construction method of a self-drilling MJS device using a lightweight cement slurry pipe, the method comprising the following steps:

[0112] S1. Positioning and setting out, setting up groundwater level and land subsidence monitoring points in the area to be reinforced, and conducting real-time monitoring of groundwater level and land subsidence;

[0113] S2. After the various pipelines of the self-drilling MJS device for lightweight cement soil reinforcement are connected, the drilling system of the self-drilling MJS device for lightweight cement soil reinforcement is started through the control console to perform the drilling operation: the motor device drives the reamer head 7 to rotate at high speed, and the reamer drill bit 7-1 and the reamer blade 7-1-1 thereon cut the soil; the cut soil and pressurized water sprayed from the pressure water outlet form a soil-water mixture, which is discharged through the mud discharge bin and mud discharge pipe 1-1; based on the groundwater level change monitoring data, the groundwater is replenished by injecting pressurized water to maintain a constant groundwater level;

[0114] S3. After drilling to the designed depth, turn off the motor device, pressure water outlet, and mud discharge bin, and stop drilling operation;

[0115] S4. The high-pressure water cutting and high-pressure cement slurry grouting reinforcement systems of the self-drilling MJS device for lightweight cement soil reinforcement are activated via the control console. High-pressure water is ejected from high-pressure water jet port 3 to cut the soil. High-pressure foamed lightweight cement slurry is then ejected from high-pressure grouting port 5 to further cut the soil and reinforce it with grouting. The drill rod is rotated and raised at a constant speed. High-pressure water jet port 3 and high-pressure grouting port 5 continue to perform high-pressure water cutting and high-pressure grouting operations, respectively.

[0116] During the high-pressure water cutting process, the pressure sensor 6 transmits the water and soil pressure data to the control console via the data acquisition instrument. The console adjusts the opening and closing degree of the mud discharge valve 4 to control the discharge of high-pressure cement slurry and high-pressure water to ensure that the water and soil pressure in the reinforced area remains constant.

[0117] The mass of the soil-water mixture is measured by a mass measuring instrument and the measured data is transmitted to the control console, which adjusts and controls the mass of the cement slurry poured into the reinforcement area to make the self-weight stress of the stratum in the reinforcement area equivalent before and after construction;

[0118] S5. After the soil grouting reinforcement is completed, the self-drilling MJS device for lightweight cement soil reinforcement is turned off, and the connections of each pipeline of the self-drilling MJS device for lightweight cement soil reinforcement are disconnected;

[0119] S6 repeats S1-S5 until all grouting reinforcement construction in the area to be reinforced is completed.

[0120] In the steps S2-S4, for soil that is prone to collapse after drilling, an outer sleeve can be set within the porous tube to prevent the collapsed soil from affecting the operation of the reamer head 7 and the integrated device 2; the outer sleeve should be consistent with the upward lifting speed of the drill rod.

[0121] The mass measuring instrument monitors the mass of the extracted mixture and adjusts the amount of cement slurry injected so that the amount of cement injected minus the amount of water lost due to evaporation of the cement soil after reinforcement is completed is equal to the amount of the extracted mixture, so as to achieve the equivalent of the self-weight stress of the stratum in the reinforced area; the amount of water lost due to evaporation of the cement soil needs to be determined through experiments.

[0122] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily conceive of other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the present invention.

Claims

1. A self-drilling aerated lightweight cement soil MJS device, characterized in that: It includes a porous tube, an integrated device, a reamer head, a pressure monitoring system, a quality measuring instrument and a control console; the pressure monitoring system includes a pressure sensor and a collector; The porous pipe, the integrated device and the reamer head are connected from top to bottom to form a drill pipe body; The porous pipe integrates a mud discharge pipe, a high-pressure cement slurry pipe, a negative pressure air pipe, a reserve air pipe, a negative pressure water pipe, a hydraulic pipe, a pressure sensor line pipe, a pressure water pipe, a power line pipe and a main air pipe; The outer side of the cylinder wall of the integrated device is provided with a high-pressure water spray port, a mud discharge port, a pressure sensor and a plurality of high-pressure grouting ports from top to bottom; and a mud discharge bin is also provided inside; The reamer head is located at the bottom of the integrated device and is connected to the mud discharge pipe through the mud discharge bin inside the integrated device; a pressure water outlet is provided at the top of the reamer head; A motor device is provided in the integrated device for driving the reamer head to rotate and cut the soil independently, so as to avoid the disturbance of the surrounding soil by the overall rotation of the drill rod when the drill rod is lifted; Each of the negative pressure air pipe, the reserve air pipe and the negative pressure water pipe forms two branches with pressure control valves in the integrated device, which are respectively connected to the mud discharge port and the mud discharge bin to assist in mud discharge and excavation; the mud discharge port and the mud discharge bin are both connected to the mud discharge pipe for mud discharge and excavation; The hydraulic pipe forms three branches with pressure control valves in the integrated device, which are connected to the mud discharge port, mud discharge bin and motor device respectively; The pressure water pipe forms two branches with pressure control valves in the integrated device, which are connected to the high-pressure water spray port on the cylinder wall of the integrated device and the pressure water outlet on the top of the reamer head respectively; The lower end of the main air pipe is connected to the high-pressure grouting port, and the upper end is connected to the air compressor; The high-pressure cement slurry pipe uses an aerated cement slurry pipe or a lightweight cement slurry pipe, which is connected to the high-pressure grouting port of the integrated device; when the aerated cement slurry pipe is used, a branch air pipe is separated from the main air pipe and connected to the aerated cement slurry pipe for aerating the cement soil; when the lightweight cement slurry pipe is used, the lightweight cement slurry in the cement slurry bin contains a foaming agent; The power line pipe is used for power supply; the high-pressure water jet nozzle cuts the soil body with high-pressure water; the mud discharge port is used for discharging the soil-water mixture formed after high-pressure water cutting, and the excess cement slurry after high-pressure grouting; The mass measuring instrument is arranged in the waste liquid tank, measures the mass of the soil-water mixture pumped into the waste liquid tank through the mud discharge pipe, and transmits the measured data to the control console; The pressure sensor is connected to the collector through the wire in the pressure sensor line tube, and the collector is connected to the console; The control console is used to regulate the coordinated control operations of various pressure control valves and control the motors.

2. A self-drilling aerated lightweight cement soil MJS device according to claim 1, characterized in that: The upper end of the aerated cement slurry pipe is connected to the cement slurry bin, and the cement slurry used is mixed with an accelerator. The aerated cement slurry pipe is connected to the main air pipe through a number of branch air pipes provided with pressure control valves in the integrated device. After the aerated cement slurry pipe is connected to the branch air pipes and gas is injected, it penetrates into the main air pipe at the high-pressure grouting port to form a coaxial double-layer pipe structure connected to the high-pressure grouting port.

3. A self-drilling aerated lightweight cement soil MJS device according to claim 2, characterized in that: The pressure control valve is connected to the control console through a wire in the pressure sensor line pipe, and adjusts the air pressure in the branch air pipe according to the water and soil pressure data collected by the pressure sensor to control the gas to enter the cement slurry in the high-pressure cement slurry pipe.

4. A self-drilling aerated lightweight cement soil MJS device according to claim 1, characterized in that: The upper end of the light cement slurry pipe is connected to a cement slurry bin, and the light cement slurry in the cement slurry bin contains a foaming agent, which is divided into a first type of foaming agent and a second type of foaming agent; The first type of foaming agent is a surfactant foaming agent, The second type of foaming agent is composed of aluminum powder, iron powder, pulling powder and air entraining agent, which are mixed in a ratio of 9:9:1:1; the foaming agent is used to produce closed bubbles in cement slurry; the air entraining agent increases the number of bubbles and makes them uniform; the second type of foaming agent is adjusted in proportion based on indoor tests and field tests to adapt to more engineering scenarios.

5. A self-drilling aerated lightweight cement soil MJS device according to claim 4, characterized in that: The amount of the foaming agent added to the cement slurry bin is adjusted in real time according to the water and soil pressure data collected by the pressure sensor, and the volume of the lightweight cement soil is required to be the same as the volume of the discharged soil-water mixture.

6. A self-drilling aerated lightweight cement soil MJS device according to claim 1, characterized in that: The reamer head is composed of a reamer drill bit and a reamer ring; the reamer drill bit and the reamer ring are fixedly connected, and the reamer blade with serrations is fixedly connected to the reamer drill bit.

7. A self-drilling aerated lightweight cement soil MJS device according to claim 1, characterized in that: The mud discharge pipe discharges mud and earth through negative pressure; the prepared air pipe contains pressurized gas, which is used for pressurized hole cleaning when the pipeline is blocked; the upper end of the pressure water pipe is connected to a pressure water tank.

8. A self-drilling aerated lightweight cement soil MJS device according to claim 1, characterized in that: The high-pressure grouting ports are arranged in pairs, and at least one pair of high-pressure grouting ports is arranged on the integrated device; the diameter of the branch air pipe is determined by the gas flux to be injected into the high-pressure cement slurry pipe; the diameter of the high-pressure cement slurry pipe in the coaxial double-layer pipe structure connected to the high-pressure grouting ports is smaller than the main air pipe.

9. A self-drilling aerated lightweight cement soil MJS device according to claim 1, characterized in that: The mud discharge port is separated from the high-pressure grouting port to prevent the mud discharge port from discharging unsolidified cement slurry in the reinforcement area; the maximum outer diameter of the reamer head should be larger than the outer diameter of the porous pipe and the integrated device.

10. A construction method of a self-drilling aerated cement soil MJS device using the device according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: S1. Measurement and positioning: setting up groundwater level and ground subsidence monitoring points in the area to be reinforced to monitor the groundwater level and ground subsidence in real time; S2. After the various pipelines of the self-drilling aerated cement soil MJS device are connected, the control console is used to control the motor device to drive the reamer head to rotate at high speed, and the reamer drill bit and the reamer blade thereon cut the soil; the cut soil and the pressure water sprayed out from the pressure outlet form a soil-water mixture, which is discharged through the mud discharge bin and mud discharge pipe; according to the monitoring data of the groundwater level change, the groundwater is replenished by injecting pressure water to keep the groundwater level unchanged; S3. After drilling to the designed depth, turn off the motor device, pressure water outlet, and mud discharge bin, and stop drilling operation; S4. After the high-pressure water jet is ejected from the high-pressure water jet port to cut the soil, high-pressure cement slurry is ejected through the high-pressure grouting port for grouting reinforcement; the drill rod is rotated and lifted, and the high-pressure water jet port and the high-pressure grouting port respectively continue to perform high-pressure water cutting of the soil and high-pressure grouting reinforcement operations; if it is necessary to add air to the aerated cement slurry pipe, the pressure control valve is controlled by the control console so that the pressure gas in the branch air pipe is injected into the cement slurry of the high-pressure cement slurry pipe to form aerated cement slurry with uniformly distributed bubbles; During the high-pressure water cutting process, the control console obtains water and soil pressure data and the mass of the soil-water mixture through pressure sensors and mass measuring instruments. The console adjusts the opening and closing degree of the mud outlet valve to control the discharge of high-pressure cement slurry and high-pressure water to ensure that the water and soil pressure in the reinforcement area remains constant. S5. After the soil grouting reinforcement is completed, the self-drilling aerated cement soil MJS device is turned off, and the connections of each pipeline of the self-drilling aerated cement soil MJS device are disconnected; S6. Repeat S1-S5 until all grouting reinforcement construction in the area to be reinforced is completed.

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