CN107795749A - A prefabricated splicing pipe fitting jacking system and its construction method - Google Patents

Abstract

A prefabricated splicing pipe fitting jacking system and its construction method. The jacking system includes a main jacking mechanism and a splicing pipe arranged along the design path of the designed pipe. The inner diameter of the spliced pipe is larger than the outer diameter of the designed pipe. The spliced pipe is spliced by spliced pipe fittings. The spliced pipe fittings are strip-shaped plates, and the front and rear sides respectively protrude outward to form an axial lap, and the left and right sides respectively protrude outward to form a circumferential lap; coaxial splicing The pipe fittings are sequentially spliced along the axial direction of the spliced pipe through the axial overlapping edges, and the spliced pipe fittings on the same circumference are sequentially spliced along the circumferential direction of the spliced pipe through the circumferential overlapping edges, all of which are fastened by the connectors. The construction method of the present invention provides strong support for the excavation and jacking process by assembling temporary spliced pipelines on the design path of the designed pipeline, and adopts the method of manual excavation and pipe jacking construction, which can meet the common requirements in pipe jacking construction. construction requirements. It can be widely used in pipe jacking construction.

Description

A prefabricated splicing pipe fitting jacking system and its construction method

technical field

The invention relates to the field of underground engineering, in particular to a pipe jacking construction system and a construction method.

Background technique

With the rapid development of science and technology, technological innovation plays an important role in all walks of life. For construction enterprises, it is undoubtedly an opportunity and a challenge. Among them, pipe jacking construction, as a relatively common non-excavation construction method, is a pipeline burying construction technology with no or less excavation. When open-cut construction is difficult and the excavation depth is greater than 5 meters, the groundwater level is high , suitable for non-excavation construction, that is, pipe jacking construction technology, mainly used in pipeline projects that are difficult to excavate, such as sewage pipeline projects, water supply and drainage pipelines, natural gas and oil pipelines, communication cables, etc. It can cross rivers, tunnels, Roads, railways, mountains and any other buildings. The use of pipe jacking construction technology, firstly, no excavation or less excavation can save manpower and reduce the cost of land acquisition and demolition; second, no excavation or less excavation can minimize the disturbance to the land, reduce air pollution, and protect the surrounding area natural ecological environment.

At present, the pipe jacking construction usually adopts one-side jacking or two-side jacking, and computer control is usually used, and the laser guide control method is used to control the elevation and centerline position of the pipe. As a non-excavation construction method, pipe jacking construction uses the jacking force generated by the jacking equipment to overcome the friction between the pipe and the surrounding soil, and push the designed slope of the pipe into the soil. In layman's terms, it is a section of pipe After jacking, the next section of pipe continues to jacking. Its principle is to push the tool pipe or roadheader from the working well through the soil layer to the receiving well and hoist by means of the thrust of the main top oil cylinder, the pipeline room and the relay room. The pipeline is buried between the two wells immediately after the tool pipe or roadheader. Among them, four kinds of pipe jacking construction techniques are more common, namely, the cutting-edge propulsion method, the mud-water propulsion method, the earth pressure propulsion method, and the mud-thick propulsion method. The cutting edge propulsion method is an open type large and medium-diameter pipe propulsion method, and the other three are closed large and medium-diameter pipe propulsion methods. The muddy water propulsion method is to balance the frontal soil pressure through the cutter head and top speed, and adjust the circulating water pressure to balance Underground water pressure, without site improvement or precipitation treatment, the surface subsidence after construction is small; the earth pressure propulsion method injects a certain proportion of mixed materials into the cutting chamber, so that the soil mixture filled with the mud chamber balances the frontal soil pressure and groundwater pressure, There is no need for rear supporting devices such as mud pumps, and the cost of the whole machine is low, and no mud treatment is required, so the construction cost is low; the mud-thick propulsion method adopts the secondary grouting method, which greatly reduces friction resistance and is suitable for long-distance jacking.

Although the above-mentioned traditional pipe jacking construction method has a high degree of automation, the construction speed is fast, and the pipe elevation and centerline position accuracy is high under the condition of straight jacking under a single geological condition. However, this method requires working wells or receiving wells at both ends of the pipeline, and when obstacles are encountered during jacking and jacking of curved lines under complex geological conditions, the control deviation of pipeline elevation and centerline position accuracy is relatively large, and even cannot be achieved. Continue jacking; especially in small pipe diameters, the deviation is very large, it is necessary to continuously adjust the jacking direction and elevation, the frequency of fine-tuning is frequent, and the construction speed is slow; and in the initial stage of propulsion, the direction is mainly controlled by the main jacking cylinder, so On the one hand, it is necessary to slow down the propulsion speed of the main jack, on the other hand, it is necessary to continuously adjust the oil cylinder grouping and the deviation correction of the pipe jacking head. Sometimes the pipe jacking head is damaged and cannot work during the mechanical jacking process, and the pipe jacking head is buried in the soil and cannot be taken out. It is necessary to re-excavate the shaft at the position of the pipe jacking head and then take out the pipe jacking head. CN 103090107 A patent discloses a rectangular large-section steel structure assembled support pipe joint jacking mechanism. The advantage is that the support pipe joint replaces the traditional pipe jacking prefabricated pipe joint, reduces the dead weight of the pipe jacking, and can effectively avoid the disadvantages of not being able to use the pipe jacking for excavation , but the burial depth is limited, and it is only used in shallow burial construction at this stage.

Contents of the invention

The purpose of the present invention is to provide a jacking system for prefabricated spliced pipe fittings and its construction method, to solve the technical problems of low construction efficiency and low precision of pipe jacking under complex conditions.

To achieve the above object, the present invention adopts the following technical solutions:

A jacking system for prefabricated spliced pipe fittings, including a main jacking mechanism, and a spliced pipe arranged along the design path of the designed pipe, the inner diameter of the spliced pipe is larger than the outer diameter of the designed pipe, and the spliced pipe is spliced by spliced pipe fittings The splicing pipe fitting is a strip plate, and its front and rear sides protrude outward respectively to form an axial lap, and the left and right sides respectively protrude outward to form a circumferential lap; the coaxial splicing pipe Along the axial direction of the spliced pipe, it is sequentially spliced through the axial overlapping edge and fastened by the connecting piece. fasten.

The main jacking mechanism is arranged at the bottom of the working well, including the back plate connected to the side wall of the working well and the main jacking jack vertically connected to the back plate, and the front end of the main jacking mechanism is also connected with a pipe jacking machine head.

The cross-section of the spliced pipe is circular, polygonal or multi-curved.

The material of the spliced pipe fittings is glass fiber reinforced plastic or metal alloy.

In jacking construction, the inner diameter of the spliced pipeline is 10-20cm larger than the outer diameter of the designed pipeline.

A construction method using the prefabricated splicing pipe fitting jacking system, the specific steps are as follows

Step 1: Construction of working wells and receiving wells.

Step 2: Excavate forward along the design path at the design position of the design pipeline.

Step 3, assembling and splicing pipelines along with the excavation construction.

Step 4, repeat steps 2 and 3 until the spliced pipeline is assembled to the receiving well along the design path.

Step five, connect and install the main jacking mechanism and the pipe jacking head at the bottom of the working shaft.

Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism.

Step seven, the designed pipeline is jacked into the receiving well along the designed path, and the jacking is stopped.

Step 8: Remove and take out the main jacking mechanism and the pipe jacking head from the working well and the receiving well respectively.

Step 9: inject grout around the designed pipeline to complete the whole construction.

In the second step, one-way excavation is carried out from the working well to the receiving well, or the two-way excavation is carried out from the working well and the receiving well to the middle at the same time; Splicing pipes.

A construction method without a receiving well using the prefabricated splicing pipe fitting jacking system, for the situation where the receiving well cannot be set due to the limitation of the site or its natural conditions, the specific steps are as follows:

Step one, construction work well.

Step 2: Excavate forward along the design path at the design position of the design pipeline.

Step 3, assembling and splicing pipelines along with the excavation construction.

Step 4, repeat steps 2 and 3 to splice the pipes to the end of the design path.

Step five, connect and install the main top mechanism at the bottom of the working well.

Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism.

Step 7, the designed pipeline is jacked to the end point along the design path, and the jacking is stopped.

Step eight, remove and take out the main top mechanism.

Step 9: inject grout around the designed pipeline to complete the whole construction.

A construction method when there are obstacles using the prefabricated splicing pipe fitting jacking system, when there are obstacles on the design path of the design pipeline or the design path is a curve, the specific steps are as follows:

Step 1: Construction of working wells and receiving wells.

Step 2: Excavate forward along the design path at the design position of the design pipeline.

Step 3, assembling and splicing pipelines along with the excavation construction.

Step 4, repeat steps 2 and 3 until the spliced pipeline is assembled to the receiving well along the design path.

Step five, connect and install the main jacking mechanism and the pipe jacking head at the bottom of the working shaft.

Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism.

Step 7: With the jacking of the designed pipeline, remove the spliced pipeline in front of the pipe jacking head.

Step 8, the designed pipeline is jacked into the receiving well along the designed path, and the jacking is stopped.

Step 9: Remove and take out the main jacking mechanism and the pipe jacking head from the working well and the receiving well respectively.

Step ten, inject grout around the designed pipeline to complete the whole construction.

A construction method when the pipe jacking head of the prefabricated splicing pipe fitting jacking system is damaged, the specific steps are as follows for the damage of the pipe jacking head during the design pipeline jacking process:

Step 1: Excavate from the receiving well to the direction of the pipe jacking head along the designed path.

Step 2, assembling and splicing pipelines along with the excavation construction.

Step 3, repeat step 1 and step 2 until the spliced pipe is assembled to the position of the pipe jacking head along the design path.

Step 4, dismantle the pipe jacking head, and transport it to the receiving well through the spliced pipeline to take it out.

Step 5: Transport the new pipe jacking head through spliced pipes, and start jacking after replacement.

Step 6: With the jacking of the designed pipeline, the spliced pipeline in front of the pipe jacking head is removed.

Step seven, the designed pipeline is jacked into the receiving well along the designed path, and the jacking is stopped.

Step 8: Remove and take out the main jacking mechanism and the pipe jacking head from the working well and the receiving well respectively.

Step 9: inject grout around the designed pipeline to complete the whole construction.

Compared with the prior art, the present invention has the following characteristics and beneficial effects:

The present invention designs a set of jacking system for pipe jacking construction, assembles temporary spliced pipes on the design path of the designed pipes, provides strong support for the excavation and jacking process, and adopts the method of manual excavation and pipe jacking construction, It can meet the common construction conditions in pipe jacking construction:

The first one, under normal conditions, there are working wells and receiving wells at the same time. When the natural conditions are good, two-way excavation can be used to improve construction efficiency. The material of the splicing pipe fittings is glass fiber reinforced plastic, which has excellent process performance, simple process, and one-time molding. The characteristics of FRP are light, high strength, good corrosion resistance, high efficiency of factory prefabrication and processing, and at the same time, the spliced pipe can be dismantled along with the jacking of the designed pipe, and the assembled pipe fittings can continue to be recycled, and the cost is low.

The second method solves the construction problem without a receiving well. This method does not need to set a receiving well. At this time, the pipe jacking head is not installed. Due to the special structure and material of the spliced pipes, the forward resistance can be reduced when the head is jacked. The construction speed is fast, safe and reliable, and suitable for wide application.

The third type, spliced pipes provide guidance and support for the entire jacking process, ensuring that the pipe jacking construction has high accuracy in the elevation and center line position of the pipe jacking construction in the case of complex geological conditions or curved jacking, and solves the problem when encountering obstacles It has the advantages of fast construction speed and low cost.

The fourth type can solve the problem of taking out the pipe jacking head without increasing the vertical shaft when the pipe jacking head is damaged during the design pipeline jacking process, and then excavate and assemble the temporary spliced pipe through the receiving shaft. Yes, if the pipe jacking head is damaged, it can be transported to the receiving well along the spliced pipeline and taken out without affecting the normal work or causing damage to the soil, which is safe, reliable and efficient.

The invention can be widely used in pipe jacking construction.

Description of drawings

The present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of the construction structure of Embodiment 1 of the present invention.

Fig. 2 is a schematic diagram of the construction structure of Embodiment 2 of the present invention.

Fig. 3 is a schematic diagram of the construction structure of Embodiment 3 of the present invention.

Fig. 4 is a schematic diagram of the assembled structure of the spliced segments of the present invention.

Fig. 5 is a schematic diagram of the single-piece structure of the spliced segment of the present invention.

Reference signs: 1 - working well, 2 - receiving well, 3 - main jacking mechanism, 4 - splicing pipe fittings, 5 - pipe jacking head, 6 - design pipeline, 7 - connecting piece, 8 - obstacle.

Detailed ways

Referring to the embodiment shown in Figure 1, this prefabricated splicing pipe fitting jacking system includes a main jacking mechanism 3, and also includes splicing pipes arranged along the design path of the design pipe 6, and the inner diameter of the splicing pipe is larger than the outer diameter of the design pipe 6 , the spliced pipeline is formed by splicing the spliced pipe fittings 4 .

Referring to FIG. 5 , the spliced pipe fitting 4 is a strip plate, and its front and rear sides respectively protrude outwards to form an axial overlapping edge, and the left and right sides respectively protrude outwards to form a circumferential overlapping edge. ; Referring to Figure 4, the coaxial spliced pipe fittings 4 are sequentially spliced along the axial direction of the spliced pipe through the axial overlapping edges and fastened by the connecting piece 7, and the spliced pipe fittings 4 of the same circumference are spliced along the spliced pipe. The rings are sequentially spliced upward through the circumferential overlapping edges and fastened through the connecting pieces.

Referring to Fig. 2 and shown in Fig. 3, the main jacking mechanism 3 is arranged at the bottom of the working well 1, including the backboard connected to the side wall of the working well and the main jacking jack vertically connected to the backboard; The front end of the main jacking mechanism 3 is also connected with a pipe jacking head.

The cross-section of the spliced pipeline is circular, polygonal or multi-curved. The material of the spliced pipe fitting 4 is glass fiber reinforced plastic, steel, or aluminum alloy, and the hardness can meet the pressure of the surrounding soil. The dimension whose inner diameter is larger than the outer diameter of the designed pipeline 6 is 10-20 cm.

A construction method using the prefabricated splicing pipe fitting jacking system, the specific steps are as follows:

Step 1, construction of working well 1 and receiving well 2.

During the construction of the working well, the excavation of the earthwork at the wellhead adopts the method of mechanical excavation, and the crane is lifted; the excavation process is installed according to one grid steel frame and one cycle, and the two grid steel frames are sprayed concrete in one cycle; the excavation should be carried out along the The long axis of the shaft is carried out in sections. First, a soil bucket rest area is excavated at one end, and the earthwork at the excavation site is temporarily placed at the other end; the lifting soil bucket adopts a steel cylinder with a diameter of 1m and a height of 1.2m; Commanded by a special person, at the same time, the personnel should withdraw from the bottom of the well during the hoisting process. After the construction of the lock ring beam is completed, the surveyors first locate the plane position of the lock ring beam and the excavation line of the well circle. Because the construction stratum of the lock ring beam does not involve groundwater, it can be done when the dewatering well is not constructed. For ring beam construction, the excavation of the well ring earthwork mainly adopts the method of manual excavation combined with mechanical construction. When the mechanical excavation reaches the design depth of 0.5m from the locking ring, the remaining earthwork is manually cleaned, leveled and compacted, and the side wall is cleaned and leveled , to avoid intrusion into the structure, after the manual cleaning of the base surface is completed, the steel bars are processed and bound, the hook length of the stirrups and reinforcing bars is 10d, the connection between the main bars is lapped and tied, and the lapped length is not less than 35d . Bind the steel bars of the lock ring beam at the corresponding elevation. In order to ensure the requirements of the overlapping of the steel bars, after the binding of the lock ring beam reinforcement is completed, use the threaded steel bar to pass through the lock ring beam and insert vertically into the soil for no less than 10 days. Type layout, in order to meet the needs of the frame construction when the shaft is excavated. After the steel bars are bound, the lock ring is molded. The lock ring template is made of plywood, connected by bolts, and the back support is made of 10×10cm square wood and shelf pipes. When setting up the formwork, add concrete pads first, and then set up the formwork to ensure the thickness of the steel bar protection layer. After the formwork is set up, concrete is poured on the lock ring beam. Before pouring, check whether the position of the formwork control line is correct, the level, the size of the section and The size of the headroom meets the design requirements; when pouring concrete, it should be constructed in layers, and a chute should be provided to extend into the formwork during construction; each layer of pouring should be compacted with a plug-in vibrator according to the principle of "quick insertion and slow extraction" Vibration; when pouring concrete, arrange quality inspectors, construction workers and safety officers to stand by. Remove the formwork after the concrete strength reaches the requirement, sprinkle water immediately after the removal of the formwork, pay attention to heat preservation during construction in winter, and take effective groundwater control measures before the construction of the working well to prevent the possibility of local water stop on the upper layer. After the construction of the lock ring beam is completed and the concrete strength meets the requirements, the earthwork in the foundation pit will be excavated, and the lower side of the ring beam will be dug 1.0m deep first, and the steel grid will be installed, and the vertical steel bar and the crown beam will be integrated. Then weld and hang double-layer steel mesh sheets on the inside and outside of the steel skeleton along the pit wall. The mesh joints are all bound, and the length is not less than one mesh. The spacing of the steel grid is set. Generally, a steel grid is set every 0.5m. The upper and lower three grilles are closely arranged at the opening of the shaft. To prevent the overall sinking of the shaft wall, excavate diagonally, and other triangles are used as supports. After excavating soil at this corner, installing steel grids and spraying concrete, dig the corresponding corner. The thickness of sprayed concrete is 300mm, grade C25; the amount of accelerator is 3% to 5% of the weight of cement; the mixture is stirred by a mixer, and it can be used as it is mixed. The storage time of dry materials without accelerator should not exceed 1 Hour. The spray protection operation should be carried out in layers, sections, and parts. The spraying sequence should be from bottom to top, moving spirally along the horizontal direction. The diameter of the circle should be about 300mm, one circle at a time, and the height of each spraying should not exceed 0.5m. When spraying, it should not accumulate in one place. It is required that the spraying should be dense without leaking reinforcement, and that the surface of the sprayed concrete should be flat and straight. Before spraying, check whether the tools and equipment are complete and in good condition. There must be no dead bends in the pipeline during spraying. The spray gun is strictly forbidden to touch people under any circumstances. Spray workers must first supply air at the beginning, then turn on the machine, and then feed materials, and then turn off the air after the materials are sprayed at the end. The material is continuously and evenly supplied to the jet pump, and there is sufficient stock in the hopper when the machine is in normal operation. The working pressure of the jet machine meets the pressure at the nozzle at 0.1Mpa. The nozzle should be kept vertical to the surface to be sprayed, and a distance of 0.6-1.0m should be kept, and the water-cement ratio should be well controlled when spraying. Before each spraying, clean the part where the stubble was sprayed last time, and remove the soil on the surface to ensure the compactness of the stubble. During the construction of the working pit, it should be constructed layer by layer downwards, excavating the soil, installing the outer mesh, the inner connecting bars, installing the steel grid, the inner connecting bars, the inner mesh, and the anchor shotcrete. In order to ensure the stability of the shaft, in the working shaft, a corner brace is placed vertically every two steel grids at the four corners to improve the anti-overturning ability and stability of the shaft. In order to make it easier for people to go up and down the shaft, a safety ladder is installed in each shaft for people to go up and down. The construction of the ladder is in accordance with the requirements of the atlas, and the height and specifications are installed and constructed according to the requirements of the drawings of the atlas. The width of the ladder is 90cm, and the vertical interval of the ladder is 3m Set up a rest platform for personnel, install handrails on both sides of the ladder, and the installation of the handrails must be firm and convenient. The material of the ladder is constructed of steel plate and angle steel, and the embedded parts of the ladder must be pre-embedded in place when constructing the shaft. The bottom of the well adopts 300 thick C25 concrete spraying + steel grid, 500 thick C40 impermeable concrete cast-in-place reinforced concrete structure, and the bottom of the well is arranged with bottom grid. m sump, the sump adopts reinforced concrete structure to collect the water flow in the working pit. Lay double-layer threaded steel mesh, and pour C40 concrete 500mm thick to ensure that the bottom of the pit is flat and dry. Make the working shaft form a whole. At the same time, safety issues should be paid attention to during the construction of working wells.

After the construction of the working well is completed, the main roof mechanism is arranged in the well, mainly including the back plate, guide rail, main roof cylinder, oil pump power station, steel escalator, etc. The pipe jacking base is a prefabricated steel structure. The position of the pipe jacking base is accurately set out according to the design axis of the pipeline. The guide rail on the base is placed in the center according to the design axis of the pipe jacking and the center of the measured hole, and support reinforcement is provided to ensure the stability of the base without deformation. After the shaft is excavated to the base of the outer edge of the structure, it shall be sealed in time. The bottom of the shaft shaft adopts the structure of "bottom sealing grid + horizontal and vertical connecting bars + pouring concrete". The bottom sealing reinforcement mesh of the working shaft adopts double-layer φ22@150mm cross arrangement and pours C30 concrete. Before pouring concrete and installing the steel grid on the bottom plate of the shaft, the elevation must be checked. Only after the steel grid is correct can the steel grid be welded and concrete poured. The bottom of the shaft is constructed with an earth pit and a sump. After the jacking is completed, the temporary bottom cover will be removed. In order to ensure the stability of the supporting structure at the exit and entrance positions, reinforcing steel bars 3Ф22@100mm are installed on both sides of the exit and entrance openings, and the length of the upper and lower extensions of the openings is not less than 1m. A HW300×300×10×145mm disc support is added at the top and bottom of the shaft opening, and the upper and lower disc supports are connected to form a door frame to ensure the stability of the shaft opening and the reliable welding of the disc support and the primary lining grid. Lay a layer of 20cm foundation with C20 concrete at the bottom of the tank, the width is 50cm longer than the sleepers, and 20cm×20cm sleepers are buried inside the concrete with a depth of 13cm. The length of the sleeper should be 30cm longer than both sides of the outer edge of the guide rail, and the distance between them should be 40cm. The surface of sleepers embedded in concrete needs to be covered with linoleum. The guide rail is made of No. 24 steel rail. The two guide rails are parallel and equal in height, and the slope and center line meet the requirements. The elevation is consistent with the slope of the designed pipeline, and it is welded and fixed on the steel plate. (This part of the structure is existing)

Step 2: Excavate forward along the design path at the design position of the design pipeline 6: after the completion of the working well, manually excavate along the direction of the pipeline at the design position of the design pipeline, and determine the elevation and center of the pipe bottom every 50cm forward excavation The position of the line and the size of the opening are determined according to the outer diameter of the spliced pipe.

Step 3: Assembling and splicing pipelines along with the excavation construction: the inner diameter of the splicing pipeline is slightly larger than the outer diameter of the designed pipeline, and the splicing pipe fittings are made of glass fiber reinforced plastic or other rigid materials. The number of splicing pipe fittings can be determined according to the site conditions. Adjacent spliced pipes are previously secured by bolted connections.

Step 4, repeat step 2 and step 3 until the spliced pipeline is assembled to the receiving well along the design path: after assembling a section of spliced pipeline, continue to excavate, and then continue to assemble the spliced pipeline forward, and the adjacent two sections of spliced pipeline are also connected by bolts Fixed until the end of the piping design.

Step five, connect and install the main jacking mechanism 3 and the pipe jacking head 5 at the bottom of the working well 1 .

After splicing the pipe fittings, install the pipe jacking equipment in the working well. First, install the back. The size of the back is set by calculation. The vertical iron is set in front of the square log, and the horizontal iron is placed in front of the vertical iron. It is closely combined with the horizontal iron, and can evenly transmit the jacking force to the back; the back of the jacking pit must have sufficient strength and firmness, and can withstand the maximum force of the jack during the jacking process; the surface of the back wall must be smooth , and perpendicular to the axis of the jacking pipe to avoid eccentric compression. The plane of the back should be perpendicular to the center line of the pipeline. After the installation, install the main jacking equipment, arrange the main jacking jacks symmetrically into 2 pieces, and fix them on the combined jack frame for overall hoisting. The specifications of each jack are the same, the strokes are synchronized, the oil circuits are connected in parallel, and they work together. They are all equipped with independent control valves. The maximum stroke that extends is about 10cm less than the cylinder stroke. The oil pump equipment is located near the main jack, and a rainproof shed is installed. The oil circuit is installed straight, the corner is reduced, the joint does not leak oil, the maximum working pressure of the oil pump is not greater than 32kpa, and a pressure limiting valve and a relief valve are installed. Indicator protection devices such as pressure gauges and pressure gauges must be tested after installation, and regularly inspected and maintained during jacking to eliminate faults in time. The size and structure of the pipe jacking head must meet the requirements, and a detailed inspection must be carried out before hoisting into the pit. When the crane unloads the head, it must be stable and slow, avoid impact and collision, and be directed by a special person to ensure safety and reliability. After the machine head is placed on the guide rail, measure the directional deviation and relative height difference between the front and rear ends, and make a record. The contact surface between the machine head and the guide rail must be stable and consistent. The tool tube and the boring machine should be positioned accurately and symmetrically on both sides according to the design requirements. The machine head must connect the circuit, oil circuit, water circuit, mud pipeline and control system one by one. The components are firmly connected without leakage, installed correctly, and carefully inspected and tested for each subsystem. When installing the earthwork transportation equipment, the mud-water balance pipe jacking machine is used to output the mud through the suction dredge pump connected to the pipeline in a hydraulic mechanical way and directly transport it to the ground mud sedimentation tank with the mud discharge bypass device. During the pipe jacking process, whether the pipe enters the hole from the working pit or exits the hole, there must be a gap between the pipe and the hole, but the gap must be sealed well. If the seal is not tight, groundwater, thixotropic mud and mud sand will It flows from the gap into the pit, affecting the operation in the pit. In severe cases, it will cause the collapse of the hole and cause accidents. Therefore, the hole must be sealed. Install the water-stop rubber ring. A δ=10mm steel plate is used in the middle of the rubber ring as a barrier and to fix the rubber ring. In order to prevent the pipe jacking head from entering and exiting the working pit from flowing into muddy water, and to ensure that the thixotropic mud injected during the jacking process will not be lost, the water stop ring on the front wall must be installed in advance, and its components are embedded flange chassis, rubber plates, steel platens, washers and bolts. The flange chassis is buried in the concrete shaft in advance, the center is correct, the end surface is flat, the installation is firm, the thread opening of the bolt is properly protected, and the cement slurry is removed in advance. When installing, install the rubber plate first, then install the steel pressure plate, and then install the gasket and fasten it with a nut to prevent water flow. Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism 3: When jacking, control the jacking force, if the jacking force is too high, the pipeline will be damaged.

Step seven, the designed pipeline 6 is jacked into the receiving well along the designed path, and the jacking is stopped.

Step eight, remove and take out the main jacking mechanism 3 and the pipe jacking head 5 from the working well and the receiving well respectively.

Step 9, pouring grout around the designed pipeline 6 to complete the entire construction: the diameter of the spliced pipeline is selected according to the diameter of the designed pipeline, even if the assembled pipeline is not removed, the amount of grouting will not be affected.

In the second step, one-way excavation is carried out from the working well to the receiving well, or the two-way excavation is carried out from the working well and the receiving well to the middle at the same time; Splicing pipes.

As shown in Figure 1, a construction method without a receiving well using the prefabricated splicing pipe fitting jacking system described above is different from the above-mentioned construction method in that, in this example, it is limited by the site or its natural conditions, and it is impossible to set up a receiving well case, the specific steps are as follows:

Step 1, construction work well 1.

Step 2: Excavate forward along the design path at the design position of the design pipeline 6 .

Step 3, assembling and splicing pipelines along with the excavation construction.

Step 4, repeat steps 2 and 3 to splice the pipes to the end of the design path.

Step five, connect and install the main top mechanism 3 at the bottom of the working well 1 .

Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism 3 .

Step 7, the design pipeline 6 is jacked along the design path to the end point, and the jacking is stopped.

Step 8, dismantle and take out the main top mechanism 3.

In step nine, grout is poured around the designed pipeline 6 to complete the entire construction.

Referring to Fig. 2, a construction method using the prefabricated splicing pipe fitting jacking system when there are obstacles is different from the first embodiment in that there are obstacles 8 or 8 on the design path of the design pipeline in this example When the design path is a curve, the specific steps are as follows:

Step 1, construction of working well 1 and receiving well 2.

Step 2: Excavate forward along the design path at the design position of the design pipeline 6 .

Step 3, assembling and splicing pipelines along with the excavation construction.

Step 4, repeat steps 2 and 3 until the spliced pipeline is assembled to the receiving well along the design path.

Step five, connect and install the main jacking mechanism 3 and the pipe jacking head 5 at the bottom of the working well 1 .

Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism 3 .

Step 7: With the jacking of the designed pipeline, remove the spliced pipeline in front of the pipe jacking head.

Step 8, the designed pipeline 6 is jacked into the receiving well along the designed path, and the jacking is stopped.

Step 9: Remove and take out the main jacking mechanism 3 and the pipe jacking head 5 from the working well and the receiving well respectively.

In step ten, inject grout around the designed pipeline 6 to complete the entire construction.

Referring to Fig. 3, a construction method when the pipe jacking head of the prefabricated splicing pipe fitting jacking system is damaged, the difference from the first embodiment is that in this example, it is aimed at the design of the pipe jacking process, In the case of damage to the pipe jacking head, when the machine head has a mechanical failure or damage during the jacking process, the conventional construction method can only add a shaft at the head position, excavate and support it layer by layer, take out the machine head, repair or replace it Continue jacking after the machine head, and because the machine head is in close contact with the soil during the precession process, it takes time to replace the machine head after it is taken out from the working well, and the original soil structure will be destroyed during the removal process. The specific steps are as follows:

Step 1: Excavate from the receiving shaft 2 along the designed path to the direction of the pipe jacking head.

Step 2, assembling and splicing pipelines along with the excavation construction.

Step 3, repeat step 1 and step 2 until the spliced pipe is assembled to the position of the pipe jacking head along the design path.

Step 4, dismantle the pipe jacking head, and transport it to the receiving well through the spliced pipeline to take it out.

Step 5: Transport the new pipe jacking head through spliced pipes, and start jacking after replacement.

Step 6: With the jacking of the designed pipeline, the spliced pipeline in front of the pipe jacking head is removed.

Step seven, the designed pipeline 6 is jacked into the receiving well along the designed path, and the jacking is stopped.

Step eight, remove and take out the main jacking mechanism 3 and the pipe jacking head 5 from the working well and the receiving well respectively.

In step nine, grout is poured around the designed pipeline 6 to complete the entire construction.

This not only saves the time for taking out the machine head from the working well to change the machine head, improves the work efficiency, but also avoids the possibility of taking out the machine head from the working well to damage the soil, and greatly reduces the workload.

The invention can realize jacking without receiving well, and at the same time, it has high accuracy of pipeline elevation and center line position under complex geological conditions and curved jacking, and fast construction speed. The pipe fittings can be reused and the cost is low.

Claims (10)

1. A jacking system for prefabricated spliced pipe fittings, comprising a main jacking mechanism (3), characterized in that it also includes a spliced pipe arranged along the design path of the designed pipe (6), and the inner diameter of the spliced pipe is larger than the designed pipe (6) ), the spliced pipe is spliced by spliced pipe fittings (4); The spliced pipe fitting (4) is a strip plate, the front and rear sides protrude outward respectively to form an axial lap, and the left and right sides respectively protrude outward to form a circumferential lap; The coaxial spliced pipe fittings (4) are sequentially spliced along the axial direction of the spliced pipe through the axial overlapping edges and fastened by the connecting piece, and the spliced pipe fittings (4) of the same circumference pass through the circumferential Splice to the overlapping edge in turn and fasten through the connecting piece. 2. The jacking system for prefabricated spliced pipe fittings according to claim 1, characterized in that: the main jacking mechanism (3) is set at the bottom of the working well (1), including a back plate connected to the side wall of the working well and The main jacking jack vertically connected to the back panel; The front end of the main jacking mechanism (3) is also connected with a pipe jacking head (5). 3. The jacking system for prefabricated spliced pipe fittings according to claim 1, characterized in that: the cross section of the spliced pipe is circular or polygonal. 4. The jacking system for prefabricated spliced pipe fittings according to claim 1, characterized in that: the material of the spliced pipe fittings (4) is glass fiber reinforced plastic or metal alloy. 5. The jacking system for prefabricated spliced pipe fittings according to claim 1, characterized in that: the inner diameter of the spliced pipe is 10-20 cm larger than the outer diameter of the designed pipe (6). 6. A construction method for applying the prefabricated splicing pipe fitting jacking system described in any one of claims 2 to 5, characterized in that, the specific steps are as follows: Step 1, constructing the working well (1) and the receiving well (2); Step 2, digging forward along the design path at the design position of the design pipeline (6); Step 3, assembling and splicing pipelines along with the excavation construction; Step 4, repeat steps 2 and 3 until the spliced pipeline is assembled to the receiving well along the design path; Step five, connect and install the main jacking mechanism (3) and the pipe jacking head (5) at the bottom of the working well (1); Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism (3); Step 7, the design pipeline (6) is jacked into the receiving well along the design path, and the jacking is stopped; Step eight, remove and take out the main jacking mechanism (3) and pipe jacking head (5) from the working well and the receiving well respectively; In step 9, inject grout around the designed pipeline (6) to complete the whole construction. 7. The construction method according to claim 6, characterized in that: In said step 2, one-way excavation from the working well to the receiving well or two-way excavation from the working well and the receiving well to the middle at the same time; In the seventh step, along with the jacking of the designed pipeline, the spliced pipeline in front of the pipe jacking head is removed. 8. A construction method without a receiving well applying the jacking system of prefabricated splicing pipe fittings according to any one of claims 1 to 5, aimed at the situation where the receiving well cannot be set due to the limitation of the site or its natural conditions, it is characterized in that, Proceed as follows: Step one, construction work well (1); Step 2, digging forward along the design path at the design position of the design pipeline (6); Step 3, assembling and splicing pipelines along with the excavation construction; Step 4, repeat steps 2 and 3 to splice the pipeline to the end of the design path; Step five, connect and install the main top mechanism (3) at the bottom of the working well (1); Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism (3); Step 7, the design pipeline (6) is jacked along the design path to the end point, and the jacking is stopped; Step eight, remove and take out the main top mechanism (3); In step 9, inject grout around the designed pipeline (6) to complete the whole construction. 9. A construction method when there are obstacles applying the prefabricated splicing pipe fitting jacking system described in any one of claims 2 to 5, when there are obstacles (8) on the design path of the design pipeline or the design path is a curve , characterized in that the specific steps are as follows: Step 1, constructing the working well (1) and the receiving well (2); Step 2, digging forward along the design path at the design position of the design pipeline (6); Step 3, assembling and splicing pipelines along with the excavation construction; Step 4, repeat steps 2 and 3 until the spliced pipeline is assembled to the receiving well along the design path; Step five, connect and install the main jacking mechanism (3) and the pipe jacking head (5) at the bottom of the working well (1); Step 6, start jacking after adjusting the jacking height and jacking direction of the main jacking mechanism (3); Step 7, along with the jacking of the designed pipeline, remove the spliced pipeline in front of the pipe jacking head; Step 8, the design pipeline (6) is jacked into the receiving well along the design path, and the jacking is stopped; Step 9, remove and take out the main jacking mechanism (3) and the pipe jacking head (5) from the working well and the receiving well respectively; In step ten, inject grout around the designed pipeline (6) to complete the whole construction. 10. A construction method when the pipe jacking head of the prefabricated splicing pipe fitting jacking system described in any one of claims 2 to 5 is damaged, for the situation that the pipe jacking head is damaged during the design pipeline jacking process, It is characterized in that the specific steps are as follows: Step 1: Excavate from the receiving well (2) along the design path to the direction of the pipe jacking head; Step 2, assembling and splicing pipelines along with the excavation construction; Step 3, repeat step 1 and step 2 until the spliced pipe is assembled to the position of the pipe jacking head along the design path; Step 4, remove the pipe jacking head, and transport it to the receiving well through spliced pipes; Step 5, transport the new pipe jacking head through the spliced pipeline, and start jacking after replacement; Step 6, along with the jacking of the designed pipeline, remove the spliced pipeline in front of the pipe jacking head; Step 7, the design pipeline (6) is jacked into the receiving well along the design path, and the jacking is stopped; Step eight, remove and take out the main jacking mechanism (3) and pipe jacking head (5) from the working well and the receiving well respectively; In step 9, inject grout around the designed pipeline (6) to complete the whole construction.