Slurry density detection and adjustment device for pipe jacking construction

Abstract

This invention relates to a mud density detection and adjustment device for pipe jacking construction, belonging to the field of pipe jacking technology. It includes a controller, a pipe jacking machine, and a working shaft formed by excavation from the ground. The pipe jacking machine enters the soil layer through the lower side wall of the working shaft. A mud-water chamber is provided inside the pipe jacking machine. A mud treatment device and a mud-water mixing device are connected sequentially by pipelines on the ground. An inlet and an outlet are respectively provided at the bottom of the mud-water chamber. An outlet pipeline connects the outlet to the mud treatment device, and an inlet pipeline connects the mud-water mixing device to the inlet. This invention innovatively forms a framework capable of dynamically adjusting the "concentration" of the liquid medium during operation, thereby achieving fully automatic and precise adjustment of the "concentration" of the working medium. This significantly improves construction efficiency, enhances the control of face stability and reduces ground disturbance, increases the safety factor during pipe jacking, and effectively controls ground settlement.

Description

Technical Field

[0001] This utility model relates to the field of pipe jacking construction technology, and in particular to an automatic adjustment device for mud density detection in mud-water balance pipe jacking machine construction for preventing over-discharge in sand layers. Background Technology

[0002] In recent years, mechanical pipe jacking technology has developed rapidly in my country's underground engineering field. This technology boasts advantages such as minimal soil disturbance, controllable ground settlement, high mechanization, high safety and efficiency, and low carbon footprint and energy saving. It has become one of the optimal methods for trenchless construction of underground pipelines and is widely used in the construction of pipelines for water supply, drainage, sewage, gas, heating, electricity, and cables. Commonly used mechanical pipe jacking methods are divided into two categories: slurry balance type and earth pressure balance type. Slurry balance type pipe jacking relies on the cutterhead panel and slurry to maintain the stability of the excavation face, using slurry to transport the excavated material.

[0003] However, in actual construction, the soil at the front end (face) of the cutterhead of the mechanical pipe jacking equipment is uneven. With varying terrain and geological conditions, the soil layers cut by the pipe jacking machine include different soil types such as silt, silty clay, and sand (fine silt, medium-coarse sand, and gravelly sand). When these different soil types are cut and mixed into the slurry chamber of the pipe jacking machine head, the density of the slurry within the chamber changes significantly, thus affecting the slurry pressure. Simultaneously, the fluctuating density of the slurry circulates continuously in the circulation pipeline, causing further fluctuations in the density of the slurry throughout the entire slurry system. Current technology typically relies on manual experience to adjust the slurry density, which suffers from shortcomings such as adjustment lag and low accuracy.

[0004] Therefore, during the construction of slurry-balanced pipe jacking machines, when fluctuations in slurry density lead to pressure imbalance between the tunnel face and the slurry chamber, how to overcome the shortcomings of human control and achieve automated and precise control of slurry density has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0005] This invention addresses the above-mentioned problems by providing a mud density detection and adjustment device for pipe jacking construction that can adjust the mud density based on changes in mud density in the mud chamber during real-time operation, thereby ensuring pressure balance between the working face and the mud chamber.

[0006] The technical solution of this utility model is as follows: it includes a controller, a pipe jacking machine and a working well formed by excavation from the ground. The pipe jacking machine enters the soil layer through the lower side wall of the working well. A mud and water chamber is provided inside the pipe jacking machine. A mud treatment device and a mud and water mixing device are provided on the ground and connected in sequence by pipelines.

[0007] The bottom of the mud and water tank is provided with a slurry inlet and a slurry outlet respectively. A slurry outlet pipeline is connected between the slurry outlet and the mud and water treatment device, and a slurry inlet pipeline is connected between the mud and water mixing device and the slurry inlet.

[0008] A density meter one is installed outside the slurry inlet, and a density meter two is installed outside the slurry outlet;

[0009] A mud density regulating device is also provided at the rear of the mud-water mixing device. The mud density regulating device includes a thick mud tank and a clear water tank connected in parallel. The thick mud tank and the clear water tank are connected to the mud inlet pipeline through a compensating pump.

[0010] A slurry compensation valve is installed on the pipeline between the slurry tank and the compensation pump, and a clean water compensation valve is installed on the pipeline between the clean water tank and the compensation pump;

[0011] Densitometer 1, Densitometer 2, Concentrated Mud Compensation Valve, Clear Water Compensation Valve, and Compensation Pump are respectively connected to the controller.

[0012] Furthermore, a valve is provided at the rear of the density meter 1 outside the slurry inlet, and a valve is provided at the rear of the density meter 2 outside the slurry outlet.

[0013] A branch line is connected between the slurry inlet pipe at the rear of valve one and the slurry outlet pipe at the rear of valve two, and valve three is installed on the branch line.

[0014] Furthermore, valve five is installed in the middle section of the slurry inlet pipeline.

[0015] A valve four is provided in the middle section of the slurry outlet pipeline, and a slurry discharge pump is also provided in front of and / or behind the valve four.

[0016] Furthermore, a flow meter is also installed at the rear of the slurry pump.

[0017] Furthermore, a valve six is ​​also provided on the pipeline connecting the mud treatment device and the mud-water mixing device.

[0018] Furthermore, a slurry inlet pump is provided at the rear of the slurry mixing device, and the slurry inlet pump is a screw pump.

[0019] This invention ingeniously connects a regulating pipe to the slurry inlet pipe. The regulating pipe contains a concentrated slurry tank with a concentration far exceeding that of the working slurry, and a clean water tank. Density meters installed at the inlet and outlet of the slurry tank collect real-time data on the density of the working slurry in the slurry circulation system. This allows for the addition of high-density concentrated slurry to the pipeline when the working slurry density is lower than the design density, and vice versa, by adding clean water to reduce the working slurry density. Using the collected data as a criterion, this invention instructs relevant actuators to operate based on set thresholds, ultimately achieving fully automatic adjustment of the slurry density.

[0020] This invention innovatively forms a framework that can dynamically adjust the "concentration" of the liquid medium during operation, thereby achieving fully automatic and precise adjustment of the "concentration" of the working medium, which greatly improves construction efficiency, enhances the control of the working face stability and reduces ground disturbance, improves the safety factor during pipe jacking, and effectively controls ground settlement. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] In the diagram, 1 is the working shaft, 2 is the pipe section, 3 is the pipe jacking machine, 31 is the mud and water chamber, 4 is the slurry inlet pipe, 5 is the slurry outlet pipe, 6 is the regulating pipe, and 7 is the overflow recovery device.

[0023] In the diagram, D1 is density meter one, D2 is density meter two, P1 is slurry inlet pump, P2 is slurry outlet pump, P3 is compensation pump, F is flow meter, K1-K6 are valve one-valve six, Kn is thick mud compensation valve, and Kq is clear water compensation valve.

[0024] In the diagram, solid arrows indicate the direction of medium flow, while hollow arrows indicate the direction of pipe jacking machine operation. Detailed Implementation

[0025] In the description of this utility model, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," and "horizontal," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] The mud density detection and adjustment device for pipe jacking construction of this utility model is as follows: Figure 1 As shown, it includes a controller, a pipe jacking machine 3, and a working shaft 1 formed by excavation from the ground. The pipe jacking machine 3 enters the soil layer through the lower side wall of the working shaft 1. A mud and water chamber 31 is provided inside the pipe jacking machine 3. A mud treatment device and a mud and water mixing device are provided on the ground and connected in sequence by pipelines.

[0028] The bottom of the mud and water tank 31 is provided with a slurry inlet and a slurry outlet. A slurry outlet pipe 5 is connected between the slurry outlet and the mud and water treatment device, and a slurry inlet pipe 4 is connected between the mud and water mixing device and the slurry inlet.

[0029] Densitometer D1 is installed outside the slurry inlet, and densitometer D2 is installed outside the slurry outlet. Densitometer D1 and densitometer D2 are respectively connected to the controller to monitor the slurry density at the set point in real time.

[0030] This invention innovatively incorporates a mud density adjustment device at the rear of the mud-water mixing unit. This device includes a concentrated mud tank and a clear water tank connected in parallel, with the tanks connected to the inlet pipe 4 via a compensation pump P3. This is entirely different from existing technologies that manually add concentrated mud or clear water to the mud treatment unit to adjust the medium density. According to the concept of this invention, the medium density can be automatically adjusted in real time. Furthermore, considering the overall balance of the circulation system, this invention can also include an overflow recovery device 7 on the mud treatment unit to achieve a balance in both total volume and pressure with the compensation device (the increase in the concentration of the concentrated mud tank and the clear water tank).

[0031] A thick mud compensation valve Kn is installed on the pipeline between the thick mud tank and the compensation pump P3, and a clear water compensation valve Kq is installed on the pipeline between the clear water tank and the compensation pump P3.

[0032] The thick mud compensation valve Kn, the clear water compensation valve Kq, and the compensation pump P3 are respectively connected to the controller.

[0033] This allows for the control of the thick mud compensation valve Kn, the clear water compensation valve Kq, and the compensation pump P3 based on the density data collected by densitometers D1 and D2.

[0034] A valve K1 is installed at the rear of the external density meter D1 at the slurry inlet, and a valve K2 is installed at the rear of the external density meter D2 at the slurry outlet, to control the slurry inlet and outlet flow rates respectively.

[0035] A branch line connects the slurry inlet pipe 4 (after valve K1) and the slurry outlet pipe 5 (after valve K2). Valve K3 is installed on this branch line. The main purpose of valve K3 is to temporarily close the outlet pipe valve K2 when the slurry density in the slurry chamber is low and the pressure inside the chamber is lower than the working face pressure, to prevent ground subsidence caused by excessive discharge of sand or soil. The inlet pipe (valve K1) remains open. At this time, a slurry mixing device is needed to compensate for the inflow of concentrated slurry into the slurry chamber, increasing the pressure inside to balance the water and soil pressure at the working face. Simultaneously, to ensure the normal operation of the entire slurry pipeline system throughout the jacking process, the slurry pipeline must be continuously circulated. Therefore, valve K3 must be opened to ensure the normal operation of the external circulation slurry pipeline. If the entire mud-water pipeline stops working due to the closure of valve K2 at the slurry outlet, large particles in the mud that have entered the mud-water pipeline are likely to settle at the bottom of the pipeline, which will cause blockage over time, affecting the quality and efficiency of subsequent mud-water circulation.

[0036] Valve K5 is installed in the middle section of the slurry inlet pipe 4.

[0037] A valve K4 is installed in the middle section of the slurry outlet pipeline 5, and a slurry discharge pump P2 is installed before and / or after the valve K4. Since the slurry outlet pipeline 5 pumps the medium upwards, if the power of one slurry discharge pump P2 is insufficient, another slurry discharge pump P2 can be added in series to ensure the return flow of the medium.

[0038] A flow meter F is also installed at the rear of the slurry pump P2. The flow meter F is an electromagnetic flow meter used to determine the flow rate of the slurry.

[0039] A valve K6 is installed on the pipeline connecting the mud treatment unit and the mud-water mixing unit to control the mud flow path and regulate the system pressure balance.

[0040] A slurry pump P1 is installed at the rear of the slurry mixing device. The slurry pump P1 is a screw pump.

[0041] The working principle of this invention will be briefly explained below with reference to the markings of the valves and pumps in the accompanying drawings.

[0042] I. Normal working conditions

[0043] K1, K2, K4, and K6 are open; K3, Kn, and Kq are closed; P1 and P2 are started; P3 is stopped.

[0044] The mud-water medium enters the mud-water chamber 31 through the slurry inlet pipe 4, and then flows back to the mud-water treatment device through the slurry outlet pipe 5 from the mud-water chamber 31.

[0045] During operation, the soil cut by the cutterhead at the front end of the pipe jacking machine 3 will enter the mud-water chamber 31, thus affecting the mud density. If the mud (mud-water) density is lower than the design value, the machine will switch to working state 2.1; if the mud density is higher than the design value, the machine will switch to working state 2.2.

[0046] 2.1 If the mud density is lower than the design value, switch to thickening mud mode.

[0047] K1, K2, K4, K6, and Kn are open; K3 and Kq are closed; P1, P2, and P3 are started.

[0048] Due to the addition of thick mud, the density of the medium in the pipeline increases. When the design value is reached, Kn is shut off and P3 is stopped.

[0049] 2.2 If the mud density is higher than the design value, switch to water replenishment mode.

[0050] K1, K2, K4, K6, and Kq are open; K3 and Kn are closed; P1, P2, and P3 are started.

[0051] Due to the introduction of clean water, the density of the medium in the pipeline decreases. When the design value is reached, Kq is shut off and P3 is stopped.

[0052] 3. The pressure inside mud and water chamber 31 is too low.

[0053] When the mud density in mud chamber 31 is low and the pressure inside mud chamber 31 is lower than the working face pressure, to prevent sand layers or soil over-discharge causing ground subsidence, slurry discharge needs to be controlled. This requires temporarily closing slurry outlet valve 2K2 while keeping inlet valve 1K1 open. At this time, a mud-water mixing device is also needed to compensate for the influx of concentrated mud into mud chamber 31, increasing the pressure inside the chamber to balance with the working face water and soil pressure. Simultaneously, to ensure the normal operation of the entire mud-water pipeline system throughout the jacking process, the mud-water pipeline needs to be continuously circulated. In this case, valve 3K3 should be opened to ensure the normal operation of the external circulation mud-water pipeline. If the entire mud-water pipeline stops working due to closing slurry outlet valve 2K2, large particles in the mud that have entered the mud-water pipeline are likely to accumulate at the bottom of the steel pipe, causing blockages over time and affecting the quality and efficiency of subsequent mud-water circulation.

[0054] It should be stated that the above-described specific embodiments are merely preferred embodiments of this utility model and the technical principles employed. Those skilled in the art should understand that various modifications, equivalent substitutions, and variations can be made to this utility model based on the technical content disclosed in this application. However, such variations, as long as they do not depart from the spirit of this utility model, should be within the protection scope of this utility model. Furthermore, some terminology used in this specification and claims is not limiting but merely for ease of description.

Claims

1. A mud density detection and adjustment device for pipe jacking construction, comprising a controller, a pipe jacking machine and a working well formed by excavation from the ground, wherein the pipe jacking machine enters the soil layer through the lower side wall of the working well, a mud-water chamber is provided inside the pipe jacking machine, and a mud treatment device and a mud-water mixing device are provided on the ground in sequence by pipelines; The bottom of the mud and water tank is provided with a slurry inlet and a slurry outlet respectively. A slurry outlet pipeline is connected between the slurry outlet and the mud and water treatment device, and a slurry inlet pipeline is connected between the mud and water mixing device and the slurry inlet. A density meter one is installed outside the slurry inlet, and a density meter two is installed outside the slurry outlet; Its features are, A mud density regulating device is also provided at the rear of the mud-water mixing device. The mud density regulating device includes a thick mud tank and a clear water tank connected in parallel. The thick mud tank and the clear water tank are connected to the mud inlet pipeline through a compensating pump. A slurry compensation valve is installed on the pipeline between the slurry tank and the compensation pump, and a clean water compensation valve is installed on the pipeline between the clean water tank and the compensation pump; Densitometer 1, Densitometer 2, Concentrated Mud Compensation Valve, Clear Water Compensation Valve, and Compensation Pump are respectively connected to the controller.

2. The mud density detection and adjustment device for pipe jacking construction according to claim 1, characterized in that, A valve is provided at the rear of the density meter 1 outside the slurry inlet, and a valve is provided at the rear of the density meter 2 outside the slurry outlet. A branch line is connected between the slurry inlet pipe at the rear of valve one and the slurry outlet pipe at the rear of valve two, and valve three is installed on the branch line.

3. The mud density detection and adjustment device for pipe jacking construction according to claim 1, characterized in that, Valve five is installed in the middle section of the slurry inlet pipeline. A valve four is provided in the middle section of the slurry outlet pipeline, and a slurry discharge pump is also provided in front of and / or behind the valve four.

4. The mud density detection and adjustment device for pipe jacking construction according to claim 3, characterized in that, A flow meter is also installed at the rear of the slurry pump.

5. The mud density detection and adjustment device for pipe jacking construction according to claim 1, characterized in that, A valve six is ​​also installed on the pipeline connecting the mud treatment device and the mud-water mixing device.

6. The mud density detection and adjustment device for pipe jacking construction according to claim 1, characterized in that, A slurry inlet pump is provided at the rear of the slurry mixing device, and the slurry inlet pump is a screw pump.

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