CN111750172A

CN111750172A - Pipe jacking construction process

Info

Publication number: CN111750172A
Application number: CN202010554657.8A
Authority: CN
Inventors: 赵辉; 张志玉; 于文津; 刘全功; 陈曦灵; 蒋碧珍
Original assignee: Shanghai Branch Cccc Third Harbor Engineering Co ltd; CCCC Third Harbor Engineering Co Ltd
Current assignee: Shanghai Branch Cccc Third Harbor Engineering Co ltd; CCCC Third Harbor Engineering Co Ltd
Priority date: 2020-06-17
Filing date: 2020-06-17
Publication date: 2020-10-09

Abstract

The invention discloses a pipe jacking construction process, which is used for pipe jacking construction through large lifting and comprises the following steps: before S1 construction, soil body reinforcement is respectively carried out on the water taking jacking pipe and the drainage jacking pipe which are designed for construction on the large lift; before S2 construction, matrix monitoring points are respectively arranged at the embankment body and the slope angle of the large embankment; s3 jacking construction: respectively jacking a water taking jacking pipe and a water draining jacking pipe through a tool head, wherein the initial jacking speed is 8-12mm/min, the normal jacking speed is 20-30mm/min, and the soil output of a large lifting position after soil body reinforcement is 102-110%; s4 deviation rectifying measurement and construction: in the jacking construction of step S3, deviation measurement is performed once every time the jacking is less than 1m, and if the deviation measurement result is greater than the deviation standard, deviation correction construction is performed. In the invention, the stability of the periphery of the embankment can be ensured during construction, and the stability of the embankment body is improved.

Description

Pipe jacking construction process

Technical Field

The invention belongs to the technical field of long-distance pipe jacking construction through embankments, and particularly relates to a pipe jacking construction process.

Background

According to survey of the engineering for taking, draining and reforming the additionally-built generating set of the power plant, the basic soil layers are as follows: silty clay, silty clay, sandy silty soil, silty clay, and silt. The water taking jacking pipe is mainly jacked in the sludge clay layer of the layer IV, and the water draining jacking pipe is mainly jacked in the sludge silty clay layer of the layer III. Based on the special geological environment, the following problems are encountered in the construction process:

(1) the drainage jacking pipes need to pass through the Changjiang river levee in the engineering, and the stability of the levee can be damaged if the operation is improper. When the jacking pipe jacks into the Yangtze river, due to the fact that the pressure of a river bottom water head is large, the phenomenon of sand flowing is prone to occurring.

(2) The diameter of the jacking pipe is large, uneven frictional resistance is caused by uneven soil around the diameter of the jacking pipe, and the jacking pipe can be deviated.

(3) The water intake jacking pipe has long jacking distance and large frictional resistance, and the jacking force of the backrest behind the jacking pipe is limited, so that the jacking force is insufficient.

Disclosure of Invention

The invention aims to provide a pipe jacking construction process for ensuring a special section and carrying out safe construction.

In order to achieve the technical effects, the invention is realized by the following technical scheme.

A pipe-jacking construction process is used for pipe-jacking construction through large lifting, and comprises the following steps:

before S1 construction, soil body reinforcement is respectively carried out on the water taking jacking pipe and the drainage jacking pipe which are designed for construction on the large lift;

before S2 construction, matrix monitoring points are respectively arranged at the embankment body and the slope angle of the large embankment;

s3 jacking construction, namely respectively jacking a water taking jacking pipe and a water draining jacking pipe through a tool head, wherein the initial jacking speed is 8-12mm/min, the normal jacking speed is 20-30mm/min, and the soil mass output of a large lifting position after soil mass reinforcement is 102-110%;

s4 deviation rectifying measurement and construction: in the jacking construction of step S3, deviation measurement is performed once every time the jacking is less than 1m, and if the deviation measurement result is greater than the deviation standard, deviation correction construction is performed.

Compared with the prior art, the matrix type monitoring points are adopted, so that the detection is more comprehensive, the matrix type monitoring points are constructed in a tunneling construction mode, the matrix type monitoring points are combined, the density is higher, the observation and detection are rigorous, and more accurate data are provided for later safety.

In the invention, the plurality of monitoring points are respectively arranged on the embankment body and the embankment corner, although the embankment body is mainly penetrated through in construction, the monitoring points arranged in the range of the slope corner can detect the data of the embankment body, thereby realizing the security of the periphery of the embankment and improving the stability of the embankment body.

In the invention, the initial jacking speed is controlled to be 8-12mm/min, so that the jacking is not suitable to be too fast in the initial stage, and the safety consideration is taken into consideration. Normally, the jacking speed is 20-30mm/min, if the jacking speed is less than 20mm/min, the whole jacking pipe construction period is influenced, and the speed is too low; if the thickness is larger than 30mm/min, the construction speed is too high, the safety of the levee is difficult to detect in time, and safety accidents are easily caused.

Further, in the present invention, the soil discharge amount is generally controlled to be about 105% in the reinforced area and about 95% in the non-reinforced area. The reinforced area has a large amount of soil output, so that more reinforcement can be realized, the reinforced area is not reinforced, the soil output is small, and only other construction in the design needs to be met, so the soil output is small.

As a further improvement of the present invention, before the step S1 of construction, the concrete step of reinforcing the soil body at the water intake top pipe designed for construction on the levee is as follows: and (3) reinforcing the soil body by adopting the jet grouting piles, wherein the reinforcing thickness of the reinforced soil body is 7-9 m.

For the large lift, the water intake jacking pipe is mainly jacked in a muddy clay layer, and the jet grouting pile is more suitable for reinforcing foundations such as sandy soil, cohesive soil, silt and the like, is simultaneously suitable for reinforcing the foundations of the existing buildings without disturbing nearby soil bodies, has the advantages of simple and portable construction equipment, small noise and vibration, high construction speed, high mechanization degree, low cost and the like, and is more suitable for foundation protection in the invention.

In the invention, if the thickness of the foundation reinforcement is less than 7m, because the diameter of the jacking pipe is larger in the invention, the thickness of the foundation reinforcement is small in jacking, and certain influence is caused, especially the whole jacking pipe is too long; and if the foundation reinforcement thickness is larger than 9m, the thickness is too thick, the foundation strength meets the requirement, and the partial waste of the foundation reinforcement construction is easily caused.

As a further improvement of the present invention, before the step S1 of constructing, the concrete step of reinforcing the soil body of the large embankment with the drainage jacking pipes designed for construction includes: and for the sections of the top pipes passing through the dike, cement mixing piles are arranged on the back surface of the large dike slope angle to form a reinforcing wall, and the thickness of the reinforcing wall is 3-5 m.

And a reinforcing wall is arranged to eliminate the influence on the large lifting in the pipe jacking construction. The reinforcing wall is arranged on the back surface of the slope angle, and the drain pipe is discharged from the back surface of the embankment, so that the reinforcing wall is arranged on the back surface, and the cement mixing pile is adopted and is generally used for improving soft soil foundations. The pile forming machine is large. The prepared pile body has low cement content and low strength. Can only be used as a composite foundation. Can be selected under the condition of good field condition. More suitable for the back surface of the invention. The thickness of the reinforcing wall is 3-5m, because the water impact is small, the thickness of the reinforcing wall is smaller than the reinforcing thickness of the large embankment.

As a further improvement of the present invention, in step S2, a matrix-type monitoring point is specifically set within the effective monitoring range of the embankment body.

According to the invention, the problem of waste of manpower and material resources and the like caused by setting monitoring points in invalid monitoring points is avoided by selecting the monitoring points in the effective monitoring range, and meanwhile, the monitoring points are set in the effective monitoring range, so that the effectiveness in construction is improved. The matrix monitoring points are adopted, so that the monitoring points have certain density, the Yangtze river levee can be protected, the breakup body caused by soil body settlement is avoided, necessary settlement observation is carried out on the levee, the settlement of the levee body is strictly controlled, and the monitoring points with certain density are selectively arranged on the levee body and a slope angle according to the importance and the danger of the levee.

As a further improvement of the present invention, the effective monitoring range is: and the vertical end limit of the effective monitoring range is formed by the distance of 30-33m from the two sides of the axis of the jacking pipe, and the horizontal end limit of the effective monitoring range is formed by the two ends of the jacking distance of the levee body jacking pipe.

In the invention, the transverse end limit is convenient to understand and is used for ensuring the jacking safety, and the vertical end limit is considered from the angle that soil body settlement easily causes the breakup of the dyke body. If the distance is less than 30m, the number of observation points is too small, and meanwhile, the dike body and the like have certain width, so that monitoring points are easy to miss; and if the distance is more than 30m, the monitoring arrangement is basically met and then the monitoring arrangement is reset, so that waste is caused.

As a further improvement of the present invention, step S2 further includes setting a number of settling points at intervals of 5m within the effective monitoring range, where the number of settling points is at least 14.

In the invention, in order to protect the great dike of the Yangtze river and avoid the damage of the dike body caused by soil body settlement, necessary settlement observation is carried out on the great dike, the settlement amount of the dike body is strictly controlled, and the settlement point can be ensured to be monitored in time by every 5m settlement point.

As a further improvement of the invention, at least 4 settling points in the 14 settling points are respectively arranged at two ends of a vertical limit and two ends of a transverse limit of the detection range, and the rest settling points are divided into two groups and are uniformly arranged at the jacking construction position.

In the invention, the limit end point is provided with the monitoring point, the limit end point is taken as a key point, and the detection arrangement of other positions is carried out, so that the reasonable arrangement of the settlement point is ensured.

As a further improvement of the present invention, in the step S4 of deviation rectifying measurement and construction, the deviation rectifying construction is assisted by a relay ring to rectify the deviation.

In the invention, the tool head posture and the thrust of the rear seat deviation rectifying oil cylinder are adjusted in time during construction for the deviation phenomenon possibly generated due to uneven soil quality in the jacking process. And the relay ring is used for auxiliary rectification.

Furthermore, the invention belongs to long-distance jacking pipes, and the anti-drag slurry can be adopted during jacking pipes to effectively reduce the side friction resistance of pipe walls, and a relay ring is added in the jacking pipe construction to reduce the jacking force of a backseat.

As a further improvement of the invention, before and after the step S2 of greatly lifting construction and before the step S3 of jacking construction, the method also comprises ventilation construction, wherein the ventilation construction is that a long-drum short-pumping combined ventilation system is installed at a position 12-15m away from the jacking construction.

According to the invention, long-drum short-suction combined ventilation is adopted, a ventilation system is arranged 12-15m away from a development machine, an air suction air cylinder and an air blowing air cylinder are respectively arranged at the left side and the right side in a pipe, the two air cylinders are overlapped for 5-10 m, a suction inlet of an exhaust fan is arranged in front, an air outlet of the air blower is arranged behind, a plurality of outer axial flow fans are arranged in the middle of the pipe, and turbid air is discharged into a well.

Further, in the jacking construction of the step S3, if the front surface of the tool head meets an obstacle, the jacking speed is 3-8 mm/min.

Further, in the step S3, the soil output of the position of the embankment not reinforced by the soil body in the jacking construction is 90% to 96%.

As a further improvement of the present invention, the step S4 is followed by a post-construction slurry replacement, wherein the slurry replacement is performed on a 90m roof pipe section under large conditions by one of cement, fly ash and water glass.

In the invention, slurry replacement is added for the purpose of plugging and protecting the orifice and the like.

Drawings

FIG. 1 is a plan view of the settling points provided by the present invention;

FIG. 2 is a plan view of a water intake jacking pipe according to the present invention;

FIG. 3 is a schematic plan sectional view of the drainage header pipe according to the present invention.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

In the invention, particularly in pipe jacking construction, the following operations are carried out:

1. carrying out large dike point arrangement monitoring, guiding construction according to the settlement condition of a monitoring point, and avoiding brute construction; an effective protection scheme is made for the embankment to ensure the safety of the embankment. Aiming at the sand running phenomenon which possibly occurs, the local air pressure is added into the soil cabin to balance the water and soil pressure of the excavation surface, so that the sand running phenomenon is prevented. The top advance can adopt in the sand layer adds local atmospheric pressure in the mud cabin in order to balance the water and soil pressure of excavation face and prevent phenomenons such as sand drift and take place, and under the great condition of top surface earthing change, easily the balance control of head, openly if meet the barrier can handle at atmospheric pressure state, excavation face soil body accessible observation window direct observation soil property change. The tool pipe in the form is improved for many times, the head is additionally provided with the soil pressure display meter, and the mud water pipeline is additionally provided with the flowmeter and the density differential pressure meter, so that the construction parameters can be more effectively and conveniently controlled, and good actual results are obtained in actual construction. The engineering belongs to long-distance pipe jacking, the resistance-reducing slurry can be adopted during pipe jacking to effectively reduce the side friction resistance of the pipe wall, and the relay ring is added in the pipe jacking construction to reduce the jacking force of the backseat.

2. Because the caliber of the jacking pipe is large, the deviation phenomenon can be generated due to uneven soil quality in the jacking process, and the posture of the tool head and the thrust of the rear seat deviation rectifying oil cylinder are adjusted in time to rectify the deviation in time in the construction process. And the relay ring is used for auxiliary rectification.

3. The jacking pipe may pass through a sandy layer during jacking, and the jacking pipe is easy to generate sand flowing phenomenon during jacking due to the large pressure of a river bottom water head, and at the moment, local air pressure can be added into the soil cabin to balance the water and soil pressure of an excavation surface, so that the sand flowing phenomenon is prevented.

Specifically, if the injected lubricating slurry can form a relatively complete slurry sleeve on the periphery of the pipe, the friction reduction effect of the long-distance pipe jacking construction process is quite satisfactory, and the friction resistance can be reduced to 3-6 KN/m2 from 12-20 KN/m2 in general. The engineering adopts two modes of synchronous grouting at the tail part of the pipe-jacking tunneling machine and grouting of a pipe section behind a relay ring to reduce drag.

The grout-filling pipe is generally arranged at the middle positions of a second section pipe section behind the relay ring, the interrupted ring, the tool head and the rear seat, and the grout-filling holes are arranged at 90 degrees. Each slurry supplementing ring is controlled by an independent valve. The lubricating slurry material mainly adopts sodium bentonite, sodium carbonate, CMC and physical property indexes: the specific gravity is 1.05-1.08 g/cm3, the viscosity is 30-40S, and the mud skin thickness is 3-5 mm. During construction, proper parameters are adjusted according to the concrete condition of soil quality.

In the invention, the protection scheme for the levee is specifically as follows:

the pipe jacking needs to cross the Yangtze river levee, and in order to prevent the damage to the Yangtze river levee caused by pipe jacking construction, the following control measures are adopted in the construction:

1) soil body reinforcement

Before pipe jacking construction, a water intake adopts a jet grouting pile to reinforce a soil body, and the thickness of the water intake is about 8 m; arranging cement mixing piles on the water-back surface of the large bank slope angle at the water outlet and the top pipe embankment passing section, wherein the wall thickness is about 4 m; so as to eliminate the influence of pipe jacking construction on the embankment. After the top pipe is finished, adopting compaction grouting to form a curtain along the axis of the levee so as to improve the physical and mechanical properties of the foundation soil of the levee; and (4) performing slurry replacement on the pipe jacking section 90 meters below the levee. The replacement material is cement, fly ash and water glass, and the aim of seepage prevention and reinforcement is achieved by controlling the settlement of the levee through mud replacement.

Specifically, after the jacking is finished, slurry of the formed slurry sleeve is replaced, the replacement slurry is cement mortar, a proper amount of fly ash is added, and the slurry is pressed by a single-screw pump in the pipe. After the slurry body is condensed (generally for 24 hours), the pipeline is removed, the sealing cover is replaced, and then the orifice is sealed.

(2) Setting monitoring points

In order to protect the great dike of the Yangtze river and avoid the breakages of the dike body caused by soil body settlement, necessary settlement observation needs to be carried out on the great dike, the settlement amount of the dike body is strictly controlled, monitoring points with certain density are selectively arranged on the great dike body and a slope angle according to the importance and the danger of the great dike, and whether the great dike is settled or not is monitored. Ground settlement observation points are arranged on the large dike jacking axis and two sides of the axis, and the settlement of the dike face is determined according to the ground settlement rate.

One point is arranged at every 5m of a measuring point of the levee, the measuring point range is 30m on each side of the axis of the jacking pipe, and 14 settlement points are arranged. The measuring point arrangement is shown in figure 1.

(3) Monitoring frequency

The river levee monitoring is carried out 24 times a day when the top pipe passes through the river levee, and 12 times a day after the top pipe passes through the river levee for two weeks. If abnormal displacement and settlement mutation of the levee are found, the frequency is encrypted to 48 times per day, and the trend of development and change is monitored and analyzed in time.

The settlement observation range is 20m before and after the pipe jacking machine head, twice every day, 20m after the tool head, 2 times every day, and once a week for later settlement observation except section settlement observation.

The monitoring engineer with abundant experience is equipped to carry out standard operation, thereby strictly, accurately, timely and effectively completing the monitoring task of the whole project.

And simultaneously inviting a dike supervisor unit to supervise, paying close attention to the safety of the dike, and carrying out tracking observation in time during the construction of the engineering jacking pipe, thereby providing observation results in time and guiding the normal construction of the engineering.

Pipe jacking construction

First, selection of tool bit

Combining the similar engineering construction experience of peripheral areas, the engineering adopts a phi 3.5m two-section twist-free eave air pressure balanced type tool head. The front surface of the grid type pipe jacking tool pipe is provided with a muddy water bin, a sealed cabin is arranged behind the muddy water bin, and soil washed by the hydraulic machine sinks into muddy water at the lower part of the muddy water bin and is discharged to a muddy water treatment device on the ground through a hydraulic transport pipeline, so that the soil is discharged hydraulically.

Its advantages are simple structure, high operability and high construction speed. The machine head is provided with corresponding sensors, pressure gauges and other display devices capable of reflecting jacking dynamics, jacking speed and mud output can be controlled at any time, various ground buildings and underground pipelines can be penetrated through, and the tool head is provided with four groups of correction oil cylinders for correction operation when needed. The jacking in the sandy soil layer can adopt the mode that local air pressure is added in a mud cabin to balance the water and soil pressure of an excavation surface so as to prevent the phenomena of sand flowing and the like, and the head part is easy to be balanced and controlled under the condition that the earth covering on the top surface is greatly changed. If the front side meets the obstacle, the obstacle can be processed in an air pressure state, and the soil body on the excavated surface can directly observe the soil property change through the observation window, so that the tool head can completely meet the construction requirements of the project.

Secondly, pipe jacking construction control

The main factors for pipe jacking construction control are as follows:

(1) keep the corresponding soil plug on the front

(2) Control of grouting quantity and grouting pressure

(3) Attitude of tool head

(4) Speed of jacking

(5) Butt welding quality of pipe jacking port

When the jacking pipe is jacked in soil layers with large permeability coefficients, such as silty clay and a small amount of sandy soil, the relation between jacking speed and soil output is fully considered to prevent ground collapse, local air pressure jacking is adopted if necessary, the two points are basic measures for protecting river levee safety, and if soil output is too fast, high-pressure water breaks a soil plug at the front end of a tool head, ground settlement is also large, and river levee protection is not favorable. Therefore, in addition to ensuring the soil plug during construction, the jacking speed and the sludge discharge amount are accurately set according to specific analysis according to the sludge discharge amount of the data measured by ground settlement, and information-based construction is adopted.

When the tool head is pushed to the position 60m in front of the large bank toe, the center of the tool head is coincided with the designed axis, and the deviation rectifying action is not allowed when the tool head passes through the large bank. The jacking speed and the mud output are strictly controlled, and the soil mass at the periphery of the pipe is subjected to double-liquid grouting to form a cement soil ring sleeve with certain compactness and certain strength, and the ring sleeve and the outer wall of the pipe are filled with thixotropic mud to reduce drag.

The initial jacking speed is not suitable to be too fast, and is generally controlled to be about 10 mm/min. The soil output of the reinforced area is generally controlled to be about 105%, and the soil output of the non-reinforced area is generally controlled to be about 95%. And (4) normally jacking, wherein the soil pressure set value is between the upper limit value and the lower limit value of the water and soil pressure, the jacking speed is controlled within 20-30mm/min, and if a front obstacle is encountered, the jacking speed is controlled within 10 mm/min. The soil output is strictly controlled to prevent over-excavation and under-excavation, and the soil output is normally controlled to be 98-100% of the theoretical soil output.

And when the jacking pipe is jacked, the jacking pipe is spliced by manual welding in the pit. The method comprises the steps of hoisting a steel pipe phi 3500m multiplied by 8m into a well, flatly placing the steel pipe in a jacking pipe track, splicing the steel pipe with a front section steel pipe, wherein the distance between adjacent longitudinal seams is more than 500mm, removing rust, oil stain and water at a welded slope before splicing, polishing the surface and avoiding unevenness. When assembling, a bridge, an inclined wedge, a jack and the like are used for assembling, the welding scar is required to be flatly polished but not lower than the base metal, and the misalignment error of the longitudinal joint after assembling is +/-1 mm. Welding after assembly: the inner seam is firstly welded and bottomed, the outer seam is subjected to back chipping treatment by a carbon plane with the diameter of 8mm, and the inner seam and the outer seam are welded simultaneously. And performing quality analysis on unqualified welding seams, determining measures and then performing rework, wherein the rework of the same part is not allowed to exceed three times.

In the invention, the concrete construction process of the jacking pipe is as follows:

in the invention, the water taking pipe is a steel pipe with the diameter of 3500mm and is divided into a top pipe section and a pile frame buried pipe section, wherein the length of the top pipe section is 639m, the wall thickness is 34mm, the elevation is from-5.0 m to-11.9 m, the gradient of the top pipe is 1.08%, the steel pipe is made of carbon structural steel with the model number Q235A, and the steel pipe is connected by welding. The jacking pipe uses a 4# pump room forebay as a jacking pipe working well, passes through a dike in the Yangtze river, jacks towards the center of the river, excavates upper-layer soil covering of the jacking pipe after the jacking pipe is finished, and cuts off the fishing tool head underwater.

The drainage jacking pipe is a DN3500 reinforced concrete pipe, the outer diameter is 4140mm, the length is about 70m, the wall thickness is 320mm, and the central elevation is-3.40 m. A5 # SMW construction method well is used as a pipe jacking working well, and a drainage valve well outside a embankment is used as a receiving well of a pipe jacking.

The length of the pipe joint of the jacking pipe is 2.5m, and the pipe joint is connected with a socket joint type F-shaped interface. The jacking pipe is a horizontal straight line jacking pipe, and a mud-water cutting air pressure balance tool head is also adopted. 6 200t main tops are equipped as main top equipment. And (4) hoisting the concrete pipe by using an 80t crawler crane on site.

First step, site layout

1. Ground field arrangement

The engineering pump house water inlet room is used as a pipe jacking working well, a 32t travelling crane is arranged on the top of the well and is responsible for hoisting steel pipes and jacking irons and hoisting the inside of the well and the ground, and an 80t crawler crane is arranged on the site of a No. 5 working well. And a temporary storage yard is additionally arranged in the site for stacking pipe joints, semi-finished products, turnover materials and the like, and the storage amount of certain pipe joints is considered in the pipe jacking site. An air compressor room, a slurry room and the like are arranged on one side of the site. The jacking control room is arranged in the open caisson, and the automatic control table, the communication and the central control are all arranged in the jacking control room. And discharging the mud discharged from the jacking pipe into a mud pit.

The pipe-jacking construction was carried out continuously for 24 hours, and one iodonium tungsten lamp was attached to each of the four corners of the site, and was used for on-site illumination at night.

2. Downhole field arrangement

And in the working well, jacking equipment such as a rigid back seat, a main jacking jack, a guide rail, rigid jacking iron, annular jacking iron and the like are arranged on the temporary back seat wall along the axis direction of the jacking pipe. And a second lower escalator seat is arranged on the side of the working well for workers to go up and down.

And the power distribution box for power supply in the pipe and in the working well is positioned in the working well. And the in-pipe measurement starting platform is arranged on an axis between the main jack and the jack, is independently connected with the concrete bottom plate and is separated from the jack bracket, so that the stability of the measurement platform during jacking is ensured.

The water conduit utilizes the pump house room of intaking as the working well, installs 2 cun mud jacking pipe, 6 cun water supply and play mud pipe, power supply, 2 cun air supply lines along the wall of a well in proper order. Distribution boxes, electric welding machines, mud water bypass devices, a rear seat main oil jacking pump truck and jacking iron stacking are arranged on the two working platforms on the two sides in the well. The mud inlet pipe, the mud discharge pipe, the mud jacking pipe, the power supply pipe and the ventilation pipe are respectively arranged at the lower left side and the lower right side of the steel pipe. The lighting in the tube adopts 36V low-voltage lighting lamps, and 1 lamp is arranged every 8 m. The high-pressure mercury lamp is used for illuminating in the open caisson.

During construction, sufficient drainage equipment should be arranged in the working well and the pipeline.

Arrangement of precautions in the workwell:

(1) when the backseat is installed, the plane of the backseat is ensured to be vertical to the axis of the top pipe, and the inclination tolerance error is +/-5 mm.

(2) The jack is mounted on a steel support with certain rigidity, the support is fixed with the bottom plate to prevent displacement, and the rear cover of the jack is required to be parallel to and tightly attached to the rear seat.

(3) And (3) checking the installation elevation and the position of the jack by using an instrument to enable the axis of the jack to be parallel to the axis of the jacking pipeline.

(4) Before the guide rail is installed, firstly, a theodolite is used for discharging an extension line of a pipeline center line in a well, marks are arranged at proper positions at two ends of a working well, and the marks are used as a measurement base line when the guide rail is installed and the pipeline is jacked.

(5) And releasing the track gradient according to the height difference of two ends of the pipeline, and fixing the track on a steel plate embedded in the bottom plate.

Second part, pipe jacking work system

1. Jacking system

The main jacking device of the engineering water intaking steel jacking pipe adopts 4 home-made 400t oil cylinders. The drainage pipe jacking main jacking device adopts 6 double-acting oil cylinders produced by West Germany, and the jacking force is 3000 kN/cylinder. The total jacking force of the backseat jack can be controlled according to the oil pressure, so that the jacking force corresponding to the highest oil pressure is smaller than the allowable jacking force of the backseat. The actual jacking force is controlled within 10000 (water intake jacking pipe) and 5000 (water drainage jacking pipe) KN. Each oil cylinder is provided with an independent oil circuit control system, and auxiliary deviation correction can be performed by adjusting the resultant force center of the main jacking device according to construction requirements.

2. Mud discharging system

The mud discharging system adopts a TSWA150 x 9 high-pressure water pump to pump water and uses a 6-inch pipe to convey high-pressure water, and when the mud discharging system is pushed in a long distance, one booster water pump is supposed to be connected in series at the machine head to enhance the high-pressure water conveying capacity; and high-pressure water is delivered to the tail part of the tool pipe, one path of the high-pressure water is delivered to the hydraulic mechanical equipment at the tail part of the pipe-jacking tunneling machine, and the other path of the high-pressure water is divided into a water pipe with the diameter of 50mm and enters a high-pressure water gun at the head part of the tunneling machine. The high-pressure water gun crushes soil bodies on the front side to form slurry, and the slurry is sucked out by a hydraulic machine combined with a mud-discharging non-blocking pump and is horizontally conveyed to a mud pool. When the pipe is pushed for a long distance, the sludge discharge is also in a series connection mode, and one sludge discharge pump is arranged every 200 m. When the mud is discharged, the mud can be discharged into the mud box of the working well, and then a slurry pump or a standby hydraulic machine is started to carry out secondary lifting.

3. Slurry system

(1) Resistance reduction of mud

The use of mud for drag reduction is one of the important links for reducing the frictional resistance of the jacking pipe. If the injected lubricating slurry can form a relatively complete slurry sleeve on the periphery of the pipe, the antifriction effect of the long-distance pipe jacking construction process is quite satisfactory, and the frictional resistance can be controlled to be 12-20 KN/m in general conditions²Reduced to 3-6 KN/m². The engineering adopts two modes of synchronous grouting at the tail part of the pipe-jacking tunneling machine and grouting of a pipe section behind a relay ring to reduce drag.

The grout-filling pipe is generally arranged at the middle positions of a second section pipe section behind the relay ring, the interrupted ring, the tool head and the rear seat, and the grout-filling holes are arranged at 90 degrees. Each slurry supplementing ring is controlled by an independent valve. The lubricating slurry material mainly adopts sodium bentonite, sodium carbonate, CMC and physical property indexes: the specific gravity is 1.05-1.08 g/cm³The viscosity is 30-40S, and the thickness of the mud skin is 3-5 mm. During construction, proper parameters are adjusted according to the concrete condition of soil quality.

(2) Slurry replacement

And (4) after the jacking is finished, replacing the slurry of the formed slurry sleeve, wherein the replacement slurry is cement mortar and is mixed with a proper amount of fly ash, and the cement mortar is pressed in the pipe by a single-screw pump. After the slurry body is condensed (generally for 24 hours), the pipeline is removed, the sealing cover is replaced, and then the orifice is sealed.

(3) Grouting equipment

The BW-200 grouting pump for lubricating slurry meeting the physical performance requirements is pressed between the pipe and the outer pipe soil body through reserved grouting holes on the main pipe, the branch pipes, the ball valves and the pipe joints to wrap the steel pipe.

4. Ventilation system

In long-distance jacking pipes, ventilation is a non-negligible problem, which directly affects the health of the staff in the pipe. In order to obtain an ideal ventilation effect, the engineering adopts long-drum short-suction combined ventilation, a ventilation system is arranged at a position 12-15m away from the development machine, an air suction air cylinder and an air blowing air cylinder are respectively arranged at the left side and the right side in the pipe, the two air cylinders are overlapped by 5-10 m, a suction inlet of an exhaust fan is arranged in front, an air outlet of an air blower is arranged behind, a plurality of outer axial flow fans are arranged in the middle of the pipe, and turbid air is discharged into the well.

5. Power supply system

The working well is powered by a transformer on site, and a capacitance compensation cabinet is configured for adapting to the power supply requirement. The output end cable is divided into three paths, and the three paths are respectively used for an on-well power supply system, an underground pipe jacking machine head and an in-well main jack.

The first path is as follows: between mud: 2 × 10KW, air compressor room: 65KW, between various types: 10KW, field lighting: 20KW

And a second path: a rear seat oil pump: 2 × 22KW 44KW electric welding machine: 4 x 10KW ═ 40KW

And a third path: a tool head: the grid type local air pressure balance is 255kw (including a mud discharging system), and the relay: 11KW, illumination inside the tube: 10KW

The power supply system in the pipe is provided with reliable electric shock and leakage protection measures. The electricity used for the up-hole and down-hole and in-pipe lighting is 36v low-voltage running light. In order to meet the requirements, a 600A main power receiving cabinet is installed in a field power distribution room, 3 power distribution panels are respectively input, and the power distribution panels are distributed to all power consumption departments through 3 paths.

6. Communication and industrial television monitoring system

In order to ensure that the progress of the jacking pipe can be known in time during the construction of the jacking pipe, the construction dynamic state of the head of the jacking pipe is mastered, the safe construction is guided, and a convenient and fast communication system is installed.

(1) The in-line communication and the working surface field communication adopt HE series automatic telephone exchange and are mutually communicated by a mechanical dial telephone. The telephone is arranged in the air compressor room and the grouting shed; various workshops, central control rooms, offices, heading machines, relay rings of each path and working wells.

(2) The method comprises the following steps of (1) providing 2 low-illumination cameras, wherein one camera is arranged at an operation table of the heading machine, and monitoring various data of the operation table; one is installed in the working well to monitor the action of the main jack, and the monitor is installed in the central control room to facilitate the correct command of the technician.

6. Relay room and automatic control system thereof

(1) Combined sealed relay room

The engineering relay adopts a combined sealing relay which is self-developed by Shanghai basic company, and is mainly characterized in that a sealing device can be adjusted and combined, and can replace a worn sealing ring under normal pressure, thereby meeting the process requirement of ultra-long distance pipe jacking.

(2) Inter-relay arrangement

The length of a straight-line section top pipe of a water taking pipe in the project is 639m, the top pipes are arranged in 3 relay rooms, 40 250KN oil cylinders are arranged in the relay rooms, the maximum jacking force is 10000KN in total, the design of the relay rooms allows the rotation angle to be 1 degrees, the relay rooms can be freely adjusted through radial adjusting spiral wires, the round angle direction can be locally or integrally adjusted as required, the water taking pipe has good water stopping performance, and each relay ring is provided with a set of stroke sensor and a limit switch which are connected with a DK-20 automatic control console.

Inter-relay placement computation

Front resistance N of tunneling machine

According to the construction experience of relevant projects in the area, the front resistance is 500KN/m²And (6) estimating.

Head-on resistance N4863 kN

Per meter of pipe wall frictional resistance: f ═ pi D · F

F-per extension of pipe wall per meter frictional resistance (KN)

D-outside diameter of tube wall (m), D3.52 m

f-unit friction resistance of pipe wall, 4KN/m²

F＝πD·f＝44.2KN/m

③ arrangement between relays

L＝(K·P－N)/F

P-Relay ring design top force (KN)

N-head-on resistance (KN)

F-per meter tube wall frictional resistance (KN/m)

K-coefficient of jacking force 0.8

L ═ 71m (0.8 × 10000-.

Fourthly, arranging a second relay ring after the first relay ring, wherein L is (K.P)/F is 181m, and arranging a relay ring at an interval of 180m

Calculating the pushing length of the main jack

L＝10000/44.2＝226m

The calculation shows that 639m jacking pipes need 3 sets of relay rings. Due to incomplete geological data, the actual number and distance of the relay rings are correspondingly adjusted according to the on-site jacking force, and the jacking pipe is guaranteed to have enough jacking force.

(3) Automatic control system

The automatic control of the relay ring adopts a ZD-20 relay console provided by a basic company to carry out program control, the console automatically sends out signals to automatically control the relay ring according to the massage wiping force during the pipe jacking process, and the relay ring console is connected with an automatic control box of a relay ring oil pump through a control cable, a relay box, a remote sensor and a limiting device and automatically controls the work of the relay ring according to a jacking program.

The relay ring automatic control platform has the following functions:

the relay rings can be controlled to carry out pipe jacking automatically/manually according to program requirements.

② the jacking procedure can be changed according to the requirement.

Thirdly, the jacking distance of each ring can be adjusted according to the stress condition.

The computer can automatically sample from the automatic control console, set the relay ring to automatically/manually work, and print various data in time for technicians to analyze.

The system can meet the requirement of pipe jacking construction control under the condition of complex geology.

5.2.5 push pipe direction control and deviation rectification

(1) Push pipe direction control

The well position provided on the ground according to the design is oriented by adopting the axis of the laser theodolite; the point location transmission in the well and the underground adopts a Su-optical J2 theodolite to transmit the axis punctuation of the jacking pipe to the underground; on a steel instrument platform in the middle of the rear jack, the error value is directly read by a laser theodolite for the deviation correction personnel to refer to for the measurement and orientation of the axis of the jacking pipe. And the total length error of the control jacking pipe is larger due to the fact that the base line in the open caisson is shorter. For this reason, the measurement personnel is required to be careful in centering the instrument and in centering the point at the back sight, and must be careful. When the pipeline leveling is carried out, an inclinometer is added to the leveling instrument. And the axis and elevation of the jacking pipe are retested at regular time, so that errors are prevented from being caused, and the quality is prevented from being influenced. And in the jacking process, drawing a jacking pipe axis track diagram according to the measurement result.

(2) Deviation correction for jacking direction of pipeline

The deviation directly influences the quality of the jacking pipe when the tool head penetrates through the wall, so that special attention needs to be paid to the tool head when the tool head penetrates through the wall, and the tool head is prevented from falling. When the jacking is started, the observation is strengthened, and excessive unearthing or quicksand generation is prevented. Ensuring the accurate jacking direction. When the tool head goes out of the hole, the head of the tool head is raised by about 0.5-1.0 cm consciously.

And (4) insisting on a duty measurement and correction principle in the jacking process. And measuring the deviation condition of the axis and the elevation of the tool head once every certain jacking distance (not more than 1 m). And informing the tool head of the correction personnel by telephone. The correcting force of each oil cylinder is given by the correcting program to correct the deviation after the microcomputer carries out comprehensive analysis.

And (5) performing small-angle deviation correction. The correction angle is small every time, preferably 10 'to 20' and not more than 0.50 degrees every time.

The device cannot be lifted and dropped greatly in the correction operation. If a large deviation has occurred somewhere, the pipe is also kept back on axis with the appropriate radius of curvature. And excessive bending stress generated by the pipeline is avoided. If necessary, measures can be taken on site, and the tool head is corrected and then pushed forward.

5.2.6 mechanical devices and labor planning

1. Main construction machinery equipment plan table

2. Labor planning

Serial number	Name (R)	Number of people
			1	Lifting worker	2
2	Machinist, bench worker	3
			3	Electrician's electric engineering	2
4	Cold working by electric welding	10
			5	Measuring tool	2
6	Slurry working machine	2
			6	General worker	40
Total up to		61

Third-part pipe jacking construction technical quality and safety guarantee measure

Quality assurance measure for pipe jacking construction technology

1. Measures for reinforcing hole and penetrating wall through jacking pipe

All jacking equipment and jacking pipe tool heads are required to be completely installed in place before jacking, and the equipment needs to be operated in a trial mode. In order to ensure absolute safety during hole punching, the outer side of the hole opening needs to be reinforced. If the outside of the opening is not reinforced, the grouting holes on the blank plate are used for compacting and grouting reinforcement to play a role in retaining water and separating mud. After the safety of the hole is ensured, the blank plate can be removed. After the blank plate is removed, the wall-through water stopping device is immediately installed. The through-wall water-stopping device is characterized in that composite rubber is used for stopping water, one to three layers of composite rubber are selected according to the pressure of a water head, and the water-stopping rubber is pre-arranged in a through-wall pipe device system, so that water can be stopped in a plane (between a blank plate and a flange) and in an axial direction (between a pipe section and a through-wall pipe). When the tool pipe penetrates through the wall, the blank plate is opened, and the tool pipe enters the wall penetrating pipe to achieve the purpose of water stopping.

2. Tool head out-of-hole anti-sinking measure

When the tool head goes out of the hole, the tool head may sink due to the self weight of the tool head when going out of the hole due to the fact that the surrounding soil body is damaged when the open caisson sinks or excessive mud water loss outside the hole is caused when going out of the hole. After the tool head is in place, the head is lifted by 5mm, and the tool head tends to move upwards when the hole is drilled. And (4) observing the state of the tool head when the tool head goes out of the hole, immediately adjusting the resultant force center of the rear seat main push jack once the sinking trend is found, and correcting the deviation by using the rear seat jack. And reinforcing measures are taken outside the hole to prevent sinking.

3. The jacking pipe passes through the reinforced area and the barrier

The jacking pipe needs to pass through the reinforcing area shortly after exiting the hole. The water taking jacking pipe needs to penetrate through a high-pressure jet grouting reinforcement area, and the drainage jacking pipe needs to penetrate through a soil body reinforced by the deep mixing pile. At the moment, a method of flushing by a high-pressure water gun or manually chiseling can be adopted according to actual conditions, and if the reinforced soil is hard, the reinforced soil needs to be chiseled in the tool head by equipment such as an air pick, a steel chisel and the like. If water or sand rushes in the chiseling process, local air pressure needs to be added in the head of the pipe jacking tool head, the water and soil pressure is balanced through the air pressure, the ground settlement caused by water and soil loss is prevented, people enter the front part of the pipe jacking tool head through the additional air lock section to chiseling construction, and the pipe jacking is guaranteed to pass through smoothly.

If the jacking pipe touches an underground unknown barrier in the jacking process, local air pressure is added in the jacking pipe tool head, personnel enter the head through the air lock section to attach an air pressure environment, and small blocks or whole blocks are taken out after manual crushing according to the size of the barrier.

4. Initial jacking anti-back-off measure

Due to the fact that the depth of the hole outlet is deep, the water and soil pressure on the front face is far larger than the frictional resistance around the pipe in the initial jacking stage. When the pipe is spliced, the main pushing jack is used for fixing the pushed part and the well wall before retracting, otherwise, the pipeline retracts after being damaged, so that the initially pushed pipe joint is limited by adding a limit on the launching rack at the rear part of the pipe joint before the main pushing jack retracts until the frictional resistance of the outer wall of the steel pipe is greater than the front water and soil pressure of the tool head, and the limit is cancelled.

5. Anti-torsion measures for pipelines

In the jacking process, due to the change of the soil around, the influence of deviation correction and the nonuniformity of equipment in a pipe can cause the pipeline to be twisted in different degrees during propulsion, and the construction quality is directly influenced. Mainly adopts the following measures to reduce the torsion action on the jacking pipe.

(1) When the equipment and the pipeline in the pipeline are installed, the balance weight with the same weight is matched on the other side of the installation equipment and the other side of the pipe according to the weight balance principle, so that the left weight and the right weight are kept balanced when the pipeline is jacked. Eliminating the factors of pipeline torsion caused by human.

(2) And during jacking, pipeline torsion indicating needles are arranged at the tool head and each relay ring. Once a slight twist is found, the twist is corrected by means of a one-sided pressure counterweight. And was fitted with 30t of weight iron, the monolith weighing 25 kg.

If the tool head is twisted, the left and right anti-torsion wing plates are pushed outwards. The longer the push-out, the greater the torque resistance, and the retraction of the wings when the tool head is balanced.

6. Pipe jacking axis control measure

The jacking pipe is carried out according to the axis and the gradient of the design requirement. Mainly is the tool head measurement and the mutual cooperation of rectifying. The correction is the main means for finishing the pipeline type and is carried out according to the following principle.

(1) The attendance and measurement are corrected: namely, the deviation condition of the axis and the elevation of the tool head is measured once every time the tool head is jacked for a certain distance. The deviation correcting personnel is informed to the tool head by telephone, and the deviation correcting personnel reports the current deviation correcting angle of the tool head, the oil pressure value of the jack in each direction, the deviation of the axis and the like to the central control room and inputs the deviation into the microcomputer. The microcomputer displays the correction method and data to correct the error.

(2) Small-angle deviation correction: the deviation correcting angle is small each time, the deviation correcting angle change value pointed out each time by the microcomputer is generally not more than 0.5 degrees, when the accumulated deviation correcting angle is too large, the microcomputer is required to be in contact with an engineer on duty to determine how to correct the deviation, and special care is needed at the moment.

(3) The deviation correcting operation can not be greatly lifted, and if a large deviation occurs at a certain position, the pipeline axis is gradually returned to the axis by keeping a proper curvature radius, so that an overlarge included angle formed between two adjacent sections is avoided.

7. Drag reducing mud management and control

The principle of combining synchronous grouting and slurry supplement is carried out during jacking, grouting holes in the tail of the tool pipe need to be effectively tracked and grouted in time, a complete and effective slurry ring sleeve is ensured to be formed, a certain amount of slurry supplement holes are carried out in the grouting holes in the pipeline, the concrete slurry supplement hole positions are arranged on the middle pipeline positions of a pipe section behind a relay and a middle pipeline position between two relays, and the grouting supplementing times and grouting amount are determined according to construction conditions. When grouting, the principle of 'pressing first and then jacking, jacking along with pressing and timely grouting supplement' must be adhered to. In order to ensure the stability of the lubricating slurry and ensure that the slurry meets the construction requirements, the slurry quality index is generally 9-10 according to the PH value and the water precipitation rate is less than 2 percent when the slurry is mixed.

V＝π(D₁ ²—D₂ ²)/4

D₁Tool tube mud groove external diameter (m), D₂Pipe section external diameter (m)

In the project, the grouting amount per prolonged meter is V-0.35 m³/m。

Safety assurance measures

1. Security assurance management system

The project manager is used as a first person responsible for project production safety and is comprehensively responsible for implementation of various safety management works of the project. And (4) checking the in-place situation of each safety measure in the engineering construction process by a project safety engineer. The safety officer, the project manager and the team leader of each type directly carry out safety management on the construction content in charge of the safety officer, the project manager and the team leader of each type.

2. Safety measures for key work

(1) Ventilation in pipes

Because the project belongs to the long-distance jacking pipe, the air in the pipe is not smooth, and harmful gases such as methane and the like may exist in the soil layer which is penetrated by the jacking pipe, effective measures are required to be taken to remove the harmful gases in order to ensure the health of operating personnel. A suction type ventilation mode is adopted in the pipe, and fresh compressed air is sent to the head part of the tool by an air compressor; three axial flow fans are arranged in the exhaust pipe to exhaust, so that the turbid air is ensured to be discharged outside in time. Toxic and harmful gas alarm devices are arranged in the tool head and at every 30m of the pipeline, and meanwhile, enough oxygen masks are equipped according to the number of constructors in the pipeline for emergency use. A fire-extinguishing system in the pipe is well-established, a dry powder fire extinguisher and a foam fire extinguisher are arranged at the relay ring, a constructor in the pipe does not allow smoking, open fire construction for drawing open fire in the pipe must be provided with fire-extinguishing certification, and a professional safety worker supervises in the field. And if the excavated soil body contains a large amount of methane and has high concentration, the pipe jacking construction is immediately stopped. The construction can be continued after the report of supervision and the agreement of owners by making detailed and careful construction schemes with engineering technicians.

(2) Electric safety for pipe jacking

Because the project is a long-distance pipe jacking, high-pressure water is used as power, but the electricity in the pipe must be paid attention to safety. The power supply system in the pipe must be equipped with reliable electric shock and leakage protection devices. The electricity used for the up-hole and down-hole and in-pipe lighting is 36v low-voltage running light. The high-voltage cable and the distribution box are guaranteed to have good insulating performance in construction, cable joints are convenient and reliable to connect, and special people are required to take charge of maintenance of electrical equipment. Meanwhile, the operating personnel must have high-voltage operation skills to ensure the operation of the operation personnel on duty.

(3) Pipe joint hoisting

The pipe jacking pipe joint needs to be hoisted into a well on the ground in the pipe jacking construction, the vertical transportation is frequent, and the pipe jacking is heavy in weight and large in size, so that people are strictly prevented from being injured due to improper hoisting operation in the construction. The equipment such as crane has a limit safety device, does not overload and periodically overhauls: the driving operation is certified by a specially-assigned person: during hoisting, two commands are provided on a construction site, one command is provided for each of the upper part and the lower part of the well: regularly checking the material rigging, finding the phenomena of standard exceeding of broken wires, damage of edges and corners of the steel wire rope and the like, and timely discarding and replacing; meanwhile, the education of constructors is strengthened, and downward throwing is strictly forbidden.

3. General safety measures

(1) The illumination in construction site, well and pipe jacking is sufficient. Safety power utilization, need of having electrician on duty in the jacking stage, checking the insulation condition of cable and wire, electrical equipment, air switch, leakage switch and power connection device

(2) The temporary climbing ladders are firmly installed and reinforced, and enclosure is arranged on the ground to prevent accidents caused by the fact that sundries fall to hurt underground workers.

(3) The organization of safety technology is in the end, the respective responsibility is clear, each operation and command personnel have a good lead in the work, and the safety personnel are arranged to track and monitor each shift. And (4) strictly executing related safety technical specifications and construction regulations and strictly prohibiting illegal operation.

(4) The BD type standard electric box is used as the electric box and the switch box, the switch electric appliance in the electric box is complete and lossless, the wiring is correct, the electric box is internally provided with the leakage protector, and reasonable rated leakage action current is selected for grading matching. The distribution box is provided with a main fuse, a branch switch, a zero-row ground row and complete power and illumination. The metal shell electric box should be protected by grounding or zero connection. The switch box and the electric equipment implement a one-machine one-gate safety. The same mobile switch box strictly prohibits both 380 volt and 220 volt voltage levels.

(5) The installation, repair or removal of the temporary power tool must be done by an electrician.

(6) And monitoring adjacent environments such as pipelines, buildings (structures), earth surface deformation and the like within 15m range on two sides of the axis of the water taking and draining jacking pipe. Once an abnormal condition occurs, the technician is immediately organized to resolve it.

Environmental protection

The main waste is a large amount of slurry generated by pipe jacking construction, the length of the pipe jacking is long, the amount of the generated slurry is very large, and if the slurry cannot be timely treated, the slurry possibly has great influence on the surrounding environment. And arranging a slurry sedimentation tank outside the dike close to the drainage outlet construction cofferdam, conveying the slurry generated by construction to the sedimentation tank, and discharging the upper clear water after three-stage sedimentation. The soil deposited at the lower part is removed by a dredger without polluting waste, and is dumped to a designated area of a maritime department, so that the environment is prevented from being polluted.

Civilized construction

(1) The two-way three-way without five-necessity is realized. Two-way connection: the sidewalk on the construction site is unblocked; the unit access channel along the construction site is smooth. And III, no: no pipeline accident occurs in the construction; no major casualty accident; the road around the construction site is smooth and has no accumulated water. Fifthly, the method comprises the following steps: the construction area and the non-construction area must be strictly separated; on the construction site, card hanging construction and card matching and post-setting of managers must be achieved; the construction marks on the construction site must be stacked orderly; the site living facilities must be clean and civilized; political work must be conducted on the jobsite to create a civilized jobsite as the primary content.

(2) The seven-man propaganda is widely developed among field personnel to fight for civilized citizens.

(3) Mud, sewage, wastewater and other turbid waste materials are prevented from flowing into sewers or river channels. During construction, various wastes are piled up at a specified place and are timely treated, and the wastes cannot be poured into rivers and household garbage containers of residents. The standardization of construction areas and living areas is realized.

(4) And establishing a civilized construction squad, organizing the civilized construction according to the regulations, establishing a civilized construction management responsibility system, and developing the standard-reaching activities of the civilized construction.

The foregoing shows and describes the general principles and broad features of the present invention and advantages thereof. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A pipe-jacking construction process is used for pipe-jacking construction through large lifting, and is characterized by comprising the following steps:

s3 jacking construction: respectively jacking a water taking jacking pipe and a water draining jacking pipe through a tool head, wherein the initial jacking speed is 8-12mm/min, the normal jacking speed is 20-30mm/min, and the soil output of a large lifting position after soil body reinforcement is 102-110%;

2. The pipe jacking construction process according to claim 1, wherein before the construction in step S1, the concrete steps of reinforcing the soil body at the water-taking pipe jacking position on the embankment where the construction is designed are as follows: and (3) reinforcing the soil body by adopting the jet grouting piles, wherein the reinforcing thickness of the reinforced soil body is 7-9 m.

3. The pipe jacking construction process according to claim 1, wherein before the construction in step S1, the concrete step of reinforcing the soil body of the drainage pipe jacking designed for construction on the levee is as follows: and for the sections of the top pipes passing through the dike, cement mixing piles are arranged on the back surface of the large dike slope angle to form a reinforcing wall, and the thickness of the reinforcing wall is 3-5 m.

4. The pipe jacking construction process according to claim 1, wherein in step S2, a matrix-type monitoring point is specifically set within an effective monitoring range of the embankment body.

5. The pipe jacking construction process according to claim 4, wherein the effective monitoring range is as follows: and the vertical end limit of the effective monitoring range is formed by the distance of 30-33m from the two sides of the axis of the jacking pipe, and the horizontal end limit of the effective monitoring range is formed by the two ends of the jacking distance of the levee body jacking pipe.

6. The pipe jacking construction process according to claim 5, wherein said step S2 further comprises setting settling points every 5m within said effective monitoring range, and the number of said settling points is at least 14.

7. The pipe jacking construction process according to claim 6, wherein at least 4 of the 14 settlement points are respectively arranged at two ends of a vertical limit and two ends of a horizontal limit of the detection range, and the rest settlement points are divided into two groups and are uniformly arranged at jacking construction positions.

8. The pipe jacking construction process of claim 1, wherein in the step S4 of deviation rectifying measurement and construction, the deviation rectifying construction is assisted by a relay ring to rectify deviation.

9. The pipe jacking construction process according to claim 1, wherein before and after the step S2 of hoisting and before the step S3 of jacking construction, the process further comprises ventilation construction, and the ventilation construction is that a long-drum short-pumping combined ventilation system is installed at a distance of 12-15m from the jacking construction.

10. The pipe jacking construction process according to claim 1, wherein the step S4 is followed by a post-construction slurry replacement, wherein the slurry replacement is performed on a 90m pipe jacking section under large conditions by one of cement, fly ash or water glass.