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Slurry balance pipe jacking machine is used in large-scale construction, used to play the role of excavation equipment. What are the advantages of the slurry balance pipe jacking machine? Let's get down to it.

Slurry balance pipe jacking machine spindle eccentricity rotary motion principle is broken in front of the slurry balanced pipe jacking machine, cutter, the opening is relatively large, so large pebbles can enter the pipe jacking machine, cutter on the face of two earth and stones imported, the opening of the area about the top section of the tube machine from 15% to 20%.

The main advantage of the slurry balance jacking machine is that:

1, by replacing the cutting hob, can carry out excavation in the ordinary soil, gravel and rock in giant.

2. During the construction process, the cutting hob can be changed from the pipe jacking machine.

3. Long distance curve driving.

4, large caliber cone crushing device can be successfully broken two times.

5 、 remote control of slurry balance pipe jacking machine and realize unmanned operation within the machine.

Protection of the surrounding environment of pipe jacking machine during construction:

1. hand pipe jacking machine. The hand dug pipe jacking machine does not have the positive support, so it is prone to collapse in the construction process and cause the ground to sink greatly. A hand dug pipe jacking machine can be considered only when the basic conditions of stability are met. The shear strength of the excavation face is disturbed, so the exposed area of the excavation face is prone to spalling and collapse. When the diameter of the tool tube is greater than 1400mm, the support shall be set on the excavation face; when the stability is poor, auxiliary measures such as air pressure method can be adopted.

2. pipe jacking machine mesh extrusion tool tube. The extruding tool pipe of the pipe jacking machine is provided with local extrusion, and the excavated area on the front face can be adjusted by a retaining steel plate. When the consistency of the clay is low and the resistance is large, the propulsion speed should be lowered properly, otherwise the propulsion speed can be increased appropriately. When a network form tool tube is used in an aqueous sandy soil, a well point dewatering must be taken to dry the soil. Hydraulic excavation must strictly limit the scope of the soil, depth, top force, jacking 122.

Follow the average stress principle of pipe jacking machine should be designed in the process, let each pass and roller can mean stress, so wear will be very balanced, extend its life, secondly, pay attention to the rolling stability problem of pipe jacking machine.

Pipe jacking machine

In the design and production, pay attention to the symmetry of the roller processing, and in advance to calculate the change to the neutral layer and the amount of materials used.

Once again, bending deformation may be problems, in the production process, this phenomenon is mainly due to uneven, the best solution is in the design of force balanced, accurate processing. Finally, in production, pay attention to the accuracy of roller processing and track arc processing and protection.

The prerequisite for the support of a pipe jacking machine, as a prerequisite for minimizing the friction resistance, is the prerequisite for the optimum supporting of the pipe jacking machine:

1., in the design process and in the push top process to accurately identify the soil layer, and according to the screening curve to grasp the soil particle distribution;

2., the excavated pressure is calculated to determine the pressing pressure of the bentonite suspension;

3. determine the mixing ratio of bentonite suspensions according to the basic particle size and test them frequently;

4. correctly prepare the pipe jacking machine and bentonite suspension bottle

6. ensure that all the jacking pipe, top pipe inlet and all jacking times have hydraulic suspension of bentonite.

The main structure of the hydraulic pipe jacking unit consists of four parts. The main part is mainly composed of two double acting hydraulic cylinders. Hydraulic pump station: equipped with diesel pumping station and motor pump station. Support plate: the action is to fix the machine and support the wall of the pit. Top and pull head: the action is to push in and pull back and enlarge the hole. This series of products mainly include: 60T/3, 80T/3, 100T/3, 120T/3, 850mm is less than or equal to the diameter of the hole diameter, the distance is less than 120 meters of construction. The machine is easy to operate, long service life and convenient maintenance. It is a necessary tool for medium and small trenchless engineering construction units.

Slurry pipe jacking machine is mainly jacking machine has wide application range, long service life, the application of pipe jacking machine in the construction of the huge, but also will rust pipe jacking machine, pipe jacking machine how to solve the problem of rusting.

To solve the problem of rusting pipe jacking machine, firstly discuss the reason about the rusty metal pipe jacking machine, oxygen in the atmosphere, water erosion and other harmful impurities, will cause discoloration or rust, rust pipe jacking machine divided into manual derusting, derusting and chemical derusting machine three categories, manual derusting wire brush, scraper. Manual derusting work grinding or polishing paste; copper and its alloys, can use the method of removing rust oil eraser, mechanical descaling technology and electric wire brush, sand blasting machine.

Electric wire brush ordinary manual electric wheel conversion; sand blasting machine is the use of compressed air 0.3-0.5mpa, diameter 1 mm quartz sand, spray to the surface of the workpiece through the gun nozzle pipe jacking machine, sand impulse will rust, chemical cleaning is the use of acidic or chemical pulp dissolved iron rust, steel pipe jacking machine using sulfuric acid, ferrous the metal is mainly using nitric acid pickling, pickling, washing, washing, drying, and refueling operations shall be carried out continuously.

How does the diamond pipe jacking machine work? The drilling path can be straight and can be bent gradually. The direction of the drill can be adjusted as it moves around the obstruction, or across the motorway, river, and rail.

During the drilling process, the drilling machine can be carried out between the launching pit and the bearing pit after being dug, or the drill hole can be drilled indirectly from the surface at the small angle of the drilling machine.

The laying of a pipe or a pipe is usually divided into two steps. First, the guide hole is drilled along the desired trajectory, and the jacking machine then goes back to enlarge the bore to increase the aperture to comply with the request of the task tube. In the second step, the back dragging process, the task pipe is connected with the reamer through a rotary joint and is extended into the extended drilling hole as the drill rod moves back. Under the demand of complex formation, or when the pore size needs to be greatly increased, the pore size can be expanded gradually by means of multi-stage reaming.

When the pipe jacking machine is in use, it is necessary to check whether the pipe jacking machine fails or not, so as to avoid unnecessary losses and personnel injuries. Now explain how to determine whether the pipe jacking machine is out of order.

Under normal circumstances, the drill pipe jacking machine, if the pipe jacking machine is now the problem, there will be the following response:

1, pipe jacking machine vibrator group short circuit, may see the pipe jacking machine smoke.

2, if the pipe jacking machine vibrator contact points and connections have discoloration, burning marks and smoke traces, etc., indicating that there may be local overheating, conductor contact bad or winding burned

3, if the abnormal vibration of vibrator pipe jacking machine, it may be the driving device is stuck or the vibration motor is fixed, bad foot bolt loosening.

4. When the speed of the pipe jacking machine is slow and has a heavy noise, it shows serious overload.

Proper examination of the jacking machine and its operation will help to improve the operation of the pipe jacking machine

1. The operation pit of the pipe jacking machine works at the depth of less than 3 meters. The small mouth area and the high water table should take the precipitation measures into consideration.

2, the soil compaction pit operation, not to set the door, but you must put on the pit wall slope, slope wall edge guarantee without activity clods.

3. When the soil is soft and the water level is high, the whole rigid support of the operation pit shall be adopted, and the pile retaining support shall be laid on the wall of the pit.

4, strictly control the length of excavation, pipe jacking machine in line with the principle of less digging and jacking, ensure construction safety, when digging, personnel shall not work outside the concrete pipe

Pipe jacking machine is a kind of essential in mechanical engineering, know how to use the pipe jacking machine is very important, the use of hydraulic jacking pipe jacking machine opportunity doesn't mean that you can correct use of pipe jacking machine, maybe one of your irregular movements, may cause some accidents.

Excavation work pit: 3.4 meters long and 2.2-2.5 meters wide. Depth: provided by the user, underground pipe network and other circumstances, it is generally recommended in the original soil layer. Or according to the diameter of the jacking pipe of the pipe jacking machine, the general diameter is larger and the digging depth is somewhat.

Two, will push the main machine into the work pit after the positive

1. first, the position of the front and rear gear plate is determined, and then the screw is adjusted by rotation, with a slight tightening force.

2. to find the level, in the top of the pipe jacking rod with a horizontal ruler alignment, when the bubble in the middle of the foot position is the best.

3., determine the top line, first set the benchmark at the opposite ideal location, use the line drop to visually detect the top pipe, the top rod and the benchmark to reach the three point line.

4. repeat the above work, check whether the pipe jacking machine is correct or not. If there is no difference, screw the screw firmly against the baffle.

Three, after the above work is correct, start the pipe jacking machine, hydraulic jacking machine start work, the top four poles should always measure its jacking direction, if there is abnormal, should be corrected.

The thirty-first Summer Olympic Games were held in Brazil, Rio De Janeiro on August 5, 2016 -21!

The spirit of the Olympic Games is to go all out to conquer ourselves.

In the Olympic Games, many athletes did not win the gold medal, but they did their best to break the record of history, to achieve their best results, did not beat their opponents, but they beat themselves. Like Fu Yuanhui said, she ran out of "field", has been satisfied.

The spirit of the Olympic Games is to strive for self-improvement and perseverance.

In order to win the final victory, the athletes after super strict, high strength and high difficulty of training; for the final victory, zaikuzailei they have not given up; even if no stand on the highest podium, they are not discouraged, continue to prepare for the next game...... This spirit of self - improvement and perseverance is worth learning by every one of us.

Just imagine, in peacetime work and study, we are every effort, no regrets? In the face of difficulties and problems, can we dare to accept the challenge and overcome ourselves? The vast number of Xin Xin people insist on learning this "self-improvement" of the Olympic spirit, so that Guangzhou Xin pipe jacking machine industry to make greater contributions!

The Olympic spirit has been deeply rooted in Xin guang!

The morning of April 24, 2016 eight, China Jianzhen Yangzhou International Half Marathon (hereinafter referred to as "Yanmar") in Jiangsu, Yangzhou start running shots. As the IAAF world half marathon gold standard event, the marathon has a total of 35 thousand athletes from 42 countries and regions around the world to participate, contestants reached the international gold standard level. A total of 34. Yangzhou Xin Xin heavy, there are 8 sports enthusiasts to participate in the event!!

After a fierce battle, the Ethiopia player Beich in 1 hours, 43 seconds won the men's championship, Kenya's Perez Jepchurch to 1 hours 7 minutes 21 seconds to break the record and won the women's champion. Although our employees failed to win a place, but this beyond the limit, never give up "Yanmar spirit", exactly with the corporate culture to Guang Xin heavy anastomosis.

This "Yanmar" proposed "fireworks in March, running heaven" slogan, adhere to the runners for the pre-season training camp for the first time, provide participants, provide perfect and thoughtful service for the runners.

According to Yangzhou net news: on the morning of April 14, 2015, Yangzhou held the 2015 China Yangzhou fireworks March international economic and Trade Tourism Festival press conference. Yangzhou Municipal Committee, executive vice mayor Ding Chun introduced in detail the current "fireworks in March" section of the situation, the Municipal Committee, publicity minister Lu Guiping attended the press conference.

Ding Chun, this is the city of Yangzhou in 2500th anniversary, the city is scheduled for April 18th -5 18 held 2015 China Yangzhou fireworks in March, international trade and Tourism Festival this year, the festival will continue frugal Festival principle, through simple, generous, atmosphere, Yangzhou deep cultural accumulation and rapid development momentum.

It is understood that the main event of this year's Tourism Festival is the opening ceremony of the 2015 China Yangzhou fireworks March international economic and Trade Tourism Festival and signing ceremony of major projects. The festival theme around the economic and trade activities are: Eighth International Food Safety Forum, the tenth Chinese jade carving boutique Expo 2015 Chinese lacquer art exhibition, on both sides of the Strait (Yangzhou) agricultural cooperation experimental zone to promote the signing, Hengfeng bank opened a branch in Yangzhou. In addition, sports activities include, Yangzhou, Slender West Lake 2015 Chinese million special stamps at the launching ceremony, 2015 Chinese Yangzhou Jianzhen International Half Marathon and Half Marathon Championships, the national champion Lin Yanmar inaugurated the activities.

This year's Tourism Festival is around the city to celebrate, to carry out a number of activities including the Qing Ying City, the city celebrates a series of lectures, city bookcase into the community to start ceremony, "old Yangzhou" activities, eleventh people, and "happy giveaway" free public garden activities, some activities will continue until the end of October, to the public enjoy your holiday, for the city to celebrate the 2500th anniversary to create a good atmosphere.

The Organizing Committee of the Tourism Festival introduces that during the "4.18" period, nearly 10000 Chinese and foreign businessmen will gather in Yangzhou and seek common development. Up to now, more than $20 million of foreign investment has been signed during the festival, with 50 new projects and 2 billion 431 million US dollars under the agreement.

According to the Yangzhou network reported: in the national 5A level Shu gang - the core area of the Slender West Lake scenic area of Yangzhou Slender West Lake tunnel length of 3.6 kilometers, design into 2 layers of two-way four lane, with large section shield machine construction of up to 14.93 meters in diameter, is the largest span in the world single hole double layer of highway tunnel. From the song clip travel time from the ruins of the ancient city of West Lake, from the past half hour shortened to 3 minutes, to become a "center line" through the ancient city of Yangzhou things, greatly ease the traffic pressure of tourism scenic area.

Chinese Railway Construction Bureau Group fourteen Slender West Lake tunnel project commander Dai Hongwei, the equivalent of five storey super large diameter shield machines through commonly known as the "old clay" section of the whole hard plastic clay layer, particles less than 0.5 microns in soil accounted for more than 90%, the formation of water easily on the cutter head into the mud cake, cause the mud pipe is blocked, if the down time is too long, easily causing the collapse of engineering technical difficulty and the risk of rare in the world.

Rectangular pipe jacking machine is a kind of important product in construction machinery. It is mainly used in the mechanized construction of the tunnel, tunnel and pipe hole in the horizontal direction. It mainly includes the tunnel boring machine (TBM, hard rock boring machine, pipe jacking machine), horizontal directional drilling, boom type roadheader and other products, the main products are TBM, while the "shield" is China popular name for this type of product. At present, the scale of China's tunneling machinery industry is about RMB 14 billion yuan. It is estimated that after several years of development, it is expected to reach the scale of 20 billion yuan, which can basically meet the needs of domestic construction, and also occupy a certain position in the international market.

Full face tunnel boring machine is the most advanced tunnel construction machine in the world. After years of technical development, it has reached mature technology and large-scale use since 1950s. At present, according to incomplete statistics, the global full face tunnel boring machine has accumulated production of more than 7000 units, retaining volume of about 4000 units.

TBM is a complex integrated system of machinery, electronics, hydraulics, control, information technology in one of the special working environment, product stability, reliability and adaptability requirements are very high, so in a long time, the development of the manufacture and use of TBM, has been made in our country industry and construction enterprises weakness. In fact, at the beginning of this century, China's TBM market and technology, basically be the United States and Japan, Europe and other major companies monopoly, such as Germany, the United States, Robbins Wirth Herrenknecht, Japan's MITSUBISHI heavy industries, Hitachi, Kawasaki heavy industries, shipbuilding, Komatsu IUK etc..

The largest section of rectangular pipe jacking machine shield jacking machine started to shield original well into the current, rectangular shield machine parts are orderly assembled construction, before the Spring Festival will be section 10.12 meters long, 7.27 meters high, weighing more than 400 tons of motorized rectangular shield jacking machine and the fault plane is 7.52 meters long, 5.42 Lane high and rectangular shield jacking machine assembly debugging after all.

The rectangular shield 7.27 meters long and 10.12 meters high, will be applied to the Zhengzhou Zhongzhou Avenue Subway Tunnel under construction, is currently the world's largest section of rectangular shield, in the design of a technical breakthrough in the key technology of the six cutter combined with control technology, composite shield excavation process to promote the design, reduce friction and large thin shell section structural strength design optimization problem.

A construction method of underground pipeline after shield construction and development is the pipe jacking, it does not need the excavation surface layer, and the ability to cross the roads, railways, rivers, buildings, underground structures and various kinds of underground pipeline. With the thrust of the main top oil cylinder and the relay room between the pipelines, the pipe jacking tool or the tunneling machine passes through the soil layer through the soil layer and is pushed into the receiving well for lifting. At the same time, the pipe behind the tool pipe or tunneling machine is buried between the two wells, so as to realize the construction method of laying underground pipelines without excavation.

Characteristic：

1, trenchless technology does not dig the ground, therefore, the upper layer of the pipe is not disturbed, and the pipe end of the pipe is not easy to produce section deformation, and its pipeline life is greater than the excavation method buried pipe.

2, the use of underground non excavation technology can save a large amount of land acquisition and demolition costs, reduce the use of 844000 houses, shorten the length of pipelines, there is a lot of economic and social benefits.

3, the construction of the noise and vibration is very small, not disturbing.

4, the existing road under the pipeline laying, does not affect traffic

The most prominent characteristic of pipe jacking construction is adaptability. According to the geological conditions, different construction conditions and design requirements, selection of pipe jacking construction way and adapt to, how to choose pipe jacking machine and the supporting equipment correctly, will be critical for the pipe jacking construction for.

Arrange the work well in the end pipe jacking method of soil, using compressed air hammer driven steel pipe or pipe tool production progress, and discharge the soil, or the use of hydraulic driven equipment and production of steel casing pipe forward, excavation machinery in the face of spiral conveyer, unearthed from work well. The outer diameter of the pipeline used in this method is generally no more than 160cm, and the advancing length is less than 80m.

- method is the use of pipe jacking pipe jacking machine tool equipment will be pushing tube or boring machine from the pit (originating wells) in passing through the soil has been pushed to the receiving pit (reach wells), installed in the pipeline system on drilling head constantly cutting soil dust, soil dust cutting by unearthed system will discharge the top edge in the edge cutting edge, conveying pipe segment forward at the same time, the laying of pipes or boring machine tool immediately after the pipeline buried in the pit two between a non excavation construction technology. In the process of jacking, the direction of pipe laying can be adjusted by laser guiding system.

Slurry pipe jacking machine is a kind of important product in construction machinery. It is mainly used in the mechanized construction of tunnel, tunnel and pipe hole in horizontal direction. It mainly includes the tunnel boring machine (TBM, hard rock boring machine, pipe jacking machine), horizontal directional drilling, boom type roadheader and other products, the main products are TBM, while the "shield" is China popular name for this type of product. At present, the scale of China's tunneling machinery industry is about RMB 14 billion yuan. It is estimated that after several years of development, it is expected to reach the scale of 20 billion yuan, which can basically meet the needs of domestic construction, and also occupy a certain position in the international market.

The size of the market leading products topped the world

Full face tunnel boring machine is the most advanced tunnel construction machine in the world. After years of technical development, it has reached mature technology and large-scale use since 1950s. At present, according to incomplete statistics, the global full face tunnel boring machine has accumulated production of more than 7000 units, retaining volume of about 4000 units.

According to the characteristics and engineering geological survey report, the soil for the pipe jacking machine 3-2 powder sand layer, easy to produce sand flow, so the pipe jacking construction may encounter some unexpected situations, such as sudden changes, soil obstacle, must take effective measures to deal with.

1) geological changes occur suddenly and become hard or soft. It can be judged by the torque of the cutter head, if suddenly became hard, is added to the water or mud soil, boring machine is provided with a hole with mud, its purpose is to add mud. If it's too soft, it's not a big deal. However, in order to prevent the soil carrying capacity from falling sharply, the first and third sections of pipe and tool head are linked together to increase their rigidity, so as to avoid sudden subsidence of the nose.

(2) if the spiral conveyor Water Leakage, unearthed close or very small mouth and at the same time, accelerate the speed, fast through the monimolimnion. If is Mingshui, in addition to the closure of the screw conveyor must be excavated out back, not to the influx of water, at the same time, find out the water as soon as possible, to be plugging. This situation is easier to deal with in a closed earth pressure balancing head.

(3) when an obstacle is encountered, grouting can be carried out in front of the head to consolidate the soil, and then the manhole on the head is opened for removal.

(4) in the process of pipe jacking construction, if there is abnormal deviation or rectification failure, it must stop within the standard of allowable deviation, analyze the cause, find out the countermeasure, and then continue to push ahead, and must not act blindly. The operating personnel must strictly comply with such a requirement: no matter what the situation, exceed the allowable deviation shall be stopped, and truthfully report the situation to analyze the reasons, to find countermeasures; there is an established accident reporting system immediately. When the accident happens, the process of operating in pipe jacking machine in its staff must understand the relations of various kinds of effective communication with each department leaders even small a little bit of error must also report a can not be sloppy.

How to achieve the most reasonable maintenance cost of rectangular pipe jacking machine, it is necessary to respect the actual situation and objective law of pipe jacking machine, and must respect science. In order to control the maintenance cost of pipe jacking machine, we should take into account the actual use environment, and generally proceed from the following aspects:

1, strengthen the maintenance of jacking machine, maintenance to repair, timely maintenance, the best time for repair and maintenance should be strengthened in the process of management, to ensure safety, schedule, quality and cost of insurance, while doing maintenance work, can repair the repair, the change is change;

2, pay attention to improve the competence of operating personnel, based on the full, whole process and whole process, all-round, technical training of the operators, the basic knowledge of further learning operation, maintenance and repair, to grasp the common method of fault diagnosis, emergency treatment measures, so as to improve the comprehensive quality of operators.

From the point of view of pipe jacking machine products, the new winner is the prerequisite to participate in competition. Pipe jacking machine manufacturers only meet the needs of the market and meet the psychological needs of consumers, so they can talk about competition.

At present, the social productive forces are increasing every day, and the demand of consumers is becoming higher and higher. The market of pipe jacking machines is experiencing unprecedented changes. "New" has become an important factor in winning customers and production. In a word, whoever wins the new technology will succeed.

The whole marketing management of the pipe jacking machine enterprise should be done well, and the joining machine of the pipe jacking machine should make sure the hard and soft terminal resources play a role, so it is necessary to establish the corresponding management system and form a management system system. Terminal management system, such as hard and soft terminal management system, organizational structure and job responsibilities, terminal information management system, to ensure that the work instructions issued, terminal information feedback terminal, the rational allocation of resources can be obtained efficiently and accurately perform.

Rectangular pipe jacking machine is a kind of construction equipment, hydraulic jacking machine is composed of four parts, the main part is the hydraulic cylinder, hydraulic pump, support plate, a push rod and pull head, the machine operation is very simple, and long service life, convenient maintenance, is a necessary tool in the construction of small non excavation in engineering.

Now in the construction industry in the use of pipe jacking machine is very broad, but many people do not use safe, in view of this situation, in order to avoid some accidents, today Xiaobian to provide the construction of pipe jacking machine safety precautions, to understand these, we can use a pipe jacking machine more safety construction the.

Important features of rectangular pipe jacking machine:

1. the construction work well of the pipe jacking machine is smaller than the shield work well, and it reduces the occupation area.

2. pipe jacking machine has the advantages of no excavation Road, no closed traffic, no moving pipelines, low noise, no dust and so on.

3. pipe jacking machine in construction, the surrounding soil disturbance is small, can effectively control the ground and pipeline subsidence. The utility model can be carried out at the vertical distance of 1 meters from the top of the pipe jacking pipe of the municipal pipe jacking machine and the passage of the pipeline without damaging the pipeline.

Points for attention in construction of pipe jacking machine:

1., if the use of the process of empty play phenomenon, do not be nervous, first relax the pump oil drain screw, the pump upside down vertical, empty record, and then tighten the screws can continue to use.

2., if there is a load, the fast connector must not be removed to avoid accidents or damage to the machine.

3. pipe jacking machine is an oil medium, so it is necessary to do the maintenance of oil and machinery, to prevent congestion or oil leakage phenomenon.

4., in the application of pipe jacking machine, construction personnel should do a good job at any time to observe the work, to ensure the normal operation of the machine, to prevent the pipe jacking machine failure.

5. in the construction of pipe jacking machine, high quality hydraulic oil is needed, and the oil must be cleaned.

6. after the completion of the construction, all parts of the pipe jacking machine need to be wiped clean, and the oil parts should be oiled.

The earth pressure slurry pipe jacking machine jacking construction method of jacking tunnel construction method is using earth pressure balanced rectangular pipe jacking machine complete the rectangular cross section, the cross section structure can reduce the rationality of land requisition and excavation area, reduce the construction cost. The utility model can be used for building subway stations, subways and underwater tunnels, side passages, etc..

1. features

1.1 using the earth pressure balanced rectangular pipe jacking machine, the rectangular section can be cut in full section to maintain the balance of earth pressure and the disturbance of surrounding soil is small.

1.2 in the same section area, rectangular tunnel can make more effective use of space than circular tunnel, and reduce underground excavation earthwork. The underground passage for pedestrian, vehicle, etc. needs no further ground preparation procedure, which saves time and reduces the construction cost by about 20%.

1.3 does not affect the original types of underground pipelines, does not affect road traffic, water transport and the ground floor of various buildings. No noise or environmental pollution during construction.

1.4 through the programmable logic controller program and various sensors to monitor the construction conditions, determine the construction parameters, the whole construction process in a controlled state, so as to effectively control the rectangular tunnel axis, jacking angle deviation and ground settlement.

2. working principle and scope of application:

2.1 working principle:

The control system of the earth pressure balance for the working principle, through the broadsword plate and a profiling knife on the positive soil whole section cutting, rotating speed change spiral machine and jacking speed to control the amount of dumping, the soil stability and control in the set pressure value range of pressure value of earth pressure in the cabin, so as to achieve the stability of soil excavation cutting surface.

2.2 scope of application:

The method is suitable for construction in clay, silty clay, silty sand and sandy silty soil. The utility model is especially suitable for the construction of rectangular sections under various underground pipelines which are not suitable for large excavation, so as to ensure that the building on the ground is not damaged.

3. benefit analysis

3.1 compared with the circular pipe jacking, there is no waste of excavation area, and make full use of the structural cross-section, so that the underground space has been effectively utilized. Underground tunnels, such as pedestrian, vehicle, and so on, do not need to be paved again. They can save a lot of time and money.

3.2 and box culvert jacking compared, because the control of earth pressure balance, small disturbance to the soil, can effectively control the surface subsidence and uplift, pipeline construction in the downtown area or building intensive situations, greatly reducing the ground and underground structures damage losses.

3.3 in the road and railway, tunnel, river pipeline construction, cannot use the slotted pipe construction, using rectangular pipe jacking machine can ensure traffic, greatly reduced due to the construction of roads, has significant social and economic benefits.

A construction method of underground pipeline after shield construction is developed as the pipe jacking construction, it does not need the excavation surface layer, and the ability to cross the roads, railways, rivers, buildings, underground structures and various kinds of underground pipeline construction, water supply and drainage, gas, electricity, communications and other pipelines are more widely used in the. However, the construction equipment, technology and management level of pipe jacking construction units are uneven, and some problems often appear in construction, which affect the quality of construction.

I. characteristics and technology of pipe jacking construction

1, pipe jacking construction characteristics

(1) in the construction of advanced pipe jacking, no road closure is required, and the selected working wells and receiving wells are located at the unused places.

(2) it needs no excavation, backfill and pavement repair, so it can reduce the total cost of the project compared with the large excavation.

(3) to avoid the bad phenomenon. Chaos stacked mud slurry hexini cycle construction method, ensure that the natural environment is not polluted, can do the construction of civilization.

(4) advanced pipe jacking method is fully automatic remote control, a worker does not need to work in the pipeline, so that not only eliminates the heavy manual workers, the workers also have enough to ensure safety.

(5) to promote the process of advanced pipe jacking boring machine and around the pipeline between the active earth pressure and passive earth pressure, the soil disturbance is few, so it will not lead to the crack of pavement settlement, avoid resurfacing.

2 、 pipe jacking construction technology

The pipe jacking construction technology is a kind of pipeline paving technology, without digging the ground, with a large thrust hydraulic jack used in pipe jacking machine with remote control device in the rear, the heading machine followed by a pipeline through soil, reach the pre designed position, this is called the top of pipe engineering. The excavation takes place in front of the pipe jacking machine, and the excavated material is pumped out through the mud circulation system to reach the surface. The basic principle of pipe jacking construction from the ground excavation pit two wells, then the tube section from work well placed by the main roof jack or relay between pushing machine of the top, the push pipe section from the well reserved hole piercing through the soil reaches the receiving well reserved port side, then through the reserved hole piercing the receiving well, the formation of pipeline construction.

At present, the construction method of pipe jacking construction used is divided into open artificial hand dug type mechanical seal and pipe jacking construction method, including mechanical pipe jacking construction method commonly used and slurry type and soil pressure balance type of two kinds of commonly used pipe jacking construction, concrete pipe, steel pipe, glass sand pipe.

Now more commonly used for pipe jacking construction of slurry balanced pipe jacking construction method, the construction principle: the guiding head cutting rotation function of clay, sand and stone will be broken by a steel pipe, injection of water, mix slurry, slurry sucked out by another pipe, the slurry in a centrifuge centrifugal dehydration, then the dry in the car to dump to spoil the place, the separated water back to the storage tank is used repeatedly. The main equipment used in the construction is information-based and fully automatic slurry balance pipe jacking machine.

Push forward the main push pipe jacking machine cylinder jacking machine by working well, and the cutter rotating cutting soil, soil cutting into the sealing chamber and the spiral conveyor, and is formed by pressing the earth pressure of soil compression screw conveyor; after rotation, conveying cutting soil. The earth pressure value in the sealing chamber can be controlled by the excavated volume or pipe jacking of screw conveyor speed, so that the earth pressure and cutting face in front of the static earth pressure and water pressure balance, so as to ensure the stability of the excavation face, prevent the ground subsidence or uplift.

In theory, in the process of jacking pipe jacking machine, wherein the pressure chamber of the P into the top soil if it is less than the active earth pressure of Pa, namely, P < Pa, the ground will sink; if P>Pa, the ground will uplift. The settlement in the construction process is a gradual process, especially in clay soil, to reach the final settlement of the time will be longer; however, the settlement process is a rapid change will immediately reflect the. The highest point of the drop is rising along the sliding surface of the soil, and finally reflects to a certain distance from the top of the pipe jacking machine. The highest point of the crack is radially extending.

Because the cutter without panel, the opening rate is close to 100%, so in the soil pressure compartment on the soil pressure gauge the measured value of earth pressure is similar to the cutting face. The above is about the working principle of pipe jacking machine.

Notice of construction of pipe jacking machine: how to accurately determine the direction of the head, the elevation and the axis of the current head are the key to success. The cutter disc needs to be rotated in the same direction after the butt joint, and the push and pull needs to be synchronized.

Symptoms: the pipeline crossing railway overpass ramp down side, cutter torque limit fluctuations, before the abnormal physical signs, return to the main hydraulic cylinder, changes disappear.

Diagnosis: there is a big obstacle in the cutterhead, which is suspected to be a concrete foundation.

Countermeasures: because of the newly built Cross railway overpass, the position of the head section are ground backfill earthwork, recommended the use of steel sheet pile supporting excavation, concrete block was broken with the pickaxe digging machine repair processing.

Tunneling head pipe jacking machine of pipeline construction machine failure and the cutter can rotate under the condition, and pipe jacking machine it is difficult in the external conditions prevent in other ways to solve this problem, with the same type of machine reverse jacking pipe jacking in the receiving well, after the docking, the push to complete a method of Piera. Jacking work.

Symptom: in the W29-W30 section construction, the top section is 140m long, from the top of 90m, a similar metal stuck sound machine, cutter torque fluctuation table. At the same time, a large number of floating oil stains were found in the mud tank. At this point, the main roof cylinder force is 60T.

Diagnosis: the internal seals are worn out and the mud water is mixed with the axle body. The main bearing is damaged and should be stopped immediately.

Countermeasures: in view of the condition of no excavation on the ground surface and the long distance of the reverse casing method, the underground quicksand is serious. Analysis of the current mechanical operation, and found that the head of the cutter in the absence of heavy load, the operation is normal. Therefore, by adopting the same type of machine head, the W29# well continues to push in and the W30# head is pulled back after the butt joint of the receiving well W30 is reversed by the same axis.