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DETAILED INTRODUCTION OF TUNNEL LINING TROLLEY

The entire mass of the tunnel lining trolley is transmitted to the supporting organization through the steel mold of the trolley, and then to the portal frame. The lining concrete is in a solid-liquid state. Large vertical pressure and lateral pressure are generated on the top and side, and a large buoyancy occurs together. When the buoyancy exceeds the straight pressure and the weight of the trolley, the trolley will float up. It will not work normally.

In order to deal with this technical problem, after careful calculation, optimized planning, and reasonable selection of each supporting position. That is, the lower longitudinal beams inside the mast are supported on the ground to prevent the side pressure from causing the mast columns to retract, and there are several horizontal supports on the outer side of the mast and the longitudinal beams of the side form, at the upper beam and the upper longitudinal beam of the mast. Several straight supports are selected (the top hydraulic cylinders are arranged on the horizontal part of the gantry at both ends, and the center is a straight supporting screw), which is uniformly distributed in the longitudinal direction of the trolley.

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STANDARD PRACTICE FOR KEY PROCEDURES OF TUNNEL CONSTRUCTION

In the process of tunnel construction, some key construction procedures are often encountered, such as: hole excavation, hollow anchor grouting quick joint, sprayed concrete, overall processing of steel arches, connecting plate processing and installation, secondary lining Rebar installation, waterproofing, secondary lining concrete, lining concrete curing, cable trench and drainage ditch, etc. What should be the standard practices for these tunnel construction content? What should be paid attention to on site construction?

Excavation

The three-step seven-step excavation method adopted in the excavation of the tunnel body is mainly to excavate the tunnel at the same time as staggering the seven excavation faces, and support at the same time to form the support as a whole, and gradually advance to the depth. It has construction Large space, high degree of mechanization, simple initial support procedures, flexible adjustments, high work efficiency, stable progress, and strong construction period security.

The tunnel body excavation is carried out in the “dual machine single hole” mode of the tunnel three-arm rock drilling rig, which effectively improves the rock drilling speed, safety factor and environmental protection effect, and improves the tunnel construction environment.

Hollow bolt grouting quick joint hole

The grouting quick connector has the following advantages:

(1) Easy and quick installation;

(2) It is closely attached to the bolt and grouting pipe connection, which can effectively ensure the grouting pressure and full grouting;

(3) Quick coupling valves can be reused, reducing construction costs;

(4) Improved the previous construction conditions of manual pipe grouting, and solved the problem of workers’ eyes being easily injured by the grout during the grouting process.

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ANALYSIS ON THE DESIGN OF TUNNEL LINING TROLLEY

The tunnel lining trolley is mainly used in the secondary lining process of the tunnel, and its main function is to help the tunnel achieve the required surface shape and size of the construction. The manufacture of tunnel lining trolleys mainly uses steel. Due to the use of steel, the tunnel lining trolley has certain strength, rigidity and shape.

In the process of tunnel construction, the use of concrete for secondary lining is a very important work, and with the development of the times, there are new requirements for concrete secondary lining work, which requires higher quality and shorter construction period. Under this trend, the use of integral steel mould lining trolleys has become an inevitable development trend.

THE WORKING PRINCIPLE OF THE TUNNEL LINING TROLLEY

The tunnel lining trolley is blocked by the excavation warehouse surface on both sides of the trolley formwork. Because the outer contour surface of the tunnel lining trolley is similar to the inner contour surface of the tunnel, the tunnel lining trolley can form a closed ring with the excavated surface. Finally, use concrete for pouring to realize the tunnel lining work. In the specific construction process, the tunnel lining trolley mainly carries out the steps of erecting the form, adjusting the center deviation of the formwork, and closing the form. Finally, the screw is used to connect the formwork and the frame, so that the concrete pouring can be completed at the end of the construction process. 

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STANDARD PRACTICE FOR KEY PROCEDURES OF TUNNEL CONSTRUCTION

In the process of tunnel construction, some key construction procedures are often encountered, such as: hole excavation, hollow anchor grouting quick joint, sprayed concrete, overall processing of steel arches, connecting plate processing and installation, secondary lining Rebar installation, waterproofing, secondary lining concrete, lining concrete curing, cable trench and drainage ditch, etc. What should be the standard practices for these tunnel construction content? What should be paid attention to on site construction?

Excavation

The three-step seven-step excavation method adopted in the excavation of the tunnel body is mainly to excavate the tunnel at the same time as staggering the seven excavation faces, and support at the same time to form the support as a whole, and gradually advance to the depth. It has construction Large space, high degree of mechanization, simple initial support procedures, flexible adjustments, high work efficiency, stable progress, and strong construction period security.

The tunnel body excavation is carried out in the “dual machine single hole” mode of the tunnel three-arm rock drilling rig, which effectively improves the rock drilling speed, safety factor and environmental protection effect, and improves the tunnel construction environment.

Hollow bolt grouting quick joint hole

The grouting quick connector has the following advantages:

(1) Easy and quick installation;

(2) It is closely attached to the bolt and grouting pipe connection, which can effectively ensure the grouting pressure and full grouting;

(3) Quick coupling valves can be reused, reducing construction costs;

(4) Improved the previous construction conditions of manual pipe grouting, and solved the problem of workers’ eyes being easily injured by the grout during the grouting process.

Click to visit for details:https://www.gf-bridge-tunnel.com/news/standard-practice-for-key-procedures-of-tunnel-construction/

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WHAT ARE THE COMMON PROBLEMS OF TUNNEL LINING TROLLEYS?

In the process of constructing the secondary lining of the tunnel, the tunnel lining trolley is a kind of special tunnel lining equipment that must be used. This is to ensure the safety of use after the tunnel is completed. The tunnel lining trolley is very important in the tunnel construction. In order to avoid problems after a lot of work, it is also necessary to maintain the tunnel lining trolley.

COMMON PROBLEMS OF LINING TROLLEY

1. What are the preparations for the installation of the lining trolley?

When the tunnel lining trolley arrives at the construction site, the following installation work needs to be prepared: installation site, sleepers and rails, lifting equipment, 6-8 installation assistants, welding machines, gas cutting equipment, wood planks, generally requiring a thickness of more than 5cm.

2. How to determine the center line of the trolley

When positioning the trolley, you must first determine the center line of the trolley. The method to determine the center line is very simple. There is a positioning cross line at the top center position. And draw the gravity vertical line, you can find the center line of the trolley.

3. How to locate

Before the tunnel lining trolley performs the lining work, the tunnel lining trolley must be positioned so that the profile section size of the tunnel lining trolley is consistent with the required size.

4. The overall deformation of the bench

After the lining trolley is impacted, it has different degrees of deformation, which is invisible to the naked eye. It will affect the forming effect after the infusion is stressed. This small degree of deformation will gradually increase the degree of deformation after multiple infusion operations. It will seriously affect the overall deformation of the platform, so the trolley mast must be hung with obvious slow-moving and no-go signs.

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HOW TO PERFORM THE POSITIONING OPERATION OF THE LINING TROLLEY?

In the construction of the tunnel, the positioning of the trolley is a very important step. Before the lining trolley is used in the tunnel for the first lining, the positioning of the trolley must be done well, so that the trolley is aligned with the center line of the tunnel. There is no problem with the positioning of the trolley. The following construction work can be carried out. If the positioning is wrong, the subsequent work may need to be adjusted. What are the positioning operations of the lining trolley?

POSITIONING OPERATION OF LINING TROLLEY

1. Carry out an inspection

Before positioning, check the electrical, hydraulic, and walking systems. Before pouring the lining trolley, clean the trolley template and apply a release agent.

2. Determine the parking location

When positioning, the surveyor uses the instrument to determine the parking position of the trolley. After the parking position is determined, in order to prevent the trolley from shifting due to vibration during the lining process, a trolley stopper can be used to fix the walking wheels.

3. Fixed elevation and horizontal plane

Raise the gantry to the required elevation and level it, fix the adjusted elevation and the horizontal plane, check it 2 to 3 times during the lining process, to prevent loosening when the force is transmitted downward to the ground, causing deviation.

4. Align the template assembly to the center line of the tunnel

Connect the template assembly to the center line of the tunnel. The template assembly can be moved horizontally on the gantry to align the template with the center line of the tunnel. After the template assembly is aligned to the center line, it is allowed to move ±100mm on the gantry. This can reduce The force of the small portal in the longitudinal direction of the tunnel.

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CONSTRUCTION TECHNOLOGY OF HYDRAULIC FORMWORK TROLLEY FOR TUNNEL INVERT

With the rapid development of tunnel construction technology, the requirements for railway tunnel construction standards are getting higher and higher, especially the requirements for the waterproof and drainage construction of long and large tunnels and the inverted arch construction are constantly increasing. Generally, the inverted arch is fully constructed and the concrete is poured at one time. In order to ensure the quality of the project, speed up the construction schedule, save construction costs, improve the degree of mechanized operation, and improve the tunnel invert construction technology and equipment, thus effectively guaranteeing its construction quality, schedule and safety, to guide the construction of similar projects.

CONSTRUCTION OF HYDRAULIC TROLLEY SYSTEM FOR TUNNEL INVERT

The tunnel invert hydraulic trolley is divided into five major systems: beam truss system, walking counterweight system, hydraulic electrical system, automatic adjustment formwork system and support fixing system. The whole invert uses two left and right hydraulic formwork trolleys, both of which are independent structures, not connected with the trestle bridge, and have no influence on other processes such as excavation of slag, and are not affected by external forces.

The longitudinal main truss is integrated with the walking system and the counterweight platform; the main truss and the arc-shaped invert template are connected by a hydraulic system, and the contraction of the arc-shaped template is completed by the hydraulic system; the end template adopts a steel template and is designed according to the thickness of the invert lining It is the upper and lower two-layer formwork. After installing the annular waterstop in the middle, it is fixed by self-made clamps;

The walking system and counterweight platform (the counterweight on the counterweight platform is a precast concrete block) is on one side of the poured concrete invert. The motor drives the walking wheels to complete the forward movement of the trolley, and the other end is equipped with an adjustable support system , After moving into position, adjust the elevation through the adjustable support system to ensure that the front and rear are at the same elevation, and anchor with anchor rods. The hydraulic system works, adjusts the arc-shaped template in place according to the design requirements and strengthens it with adjusting rods. The template and the support form a force-bearing whole, and jointly bear the external force.

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For more detailed information about the construction technology of the tunnel invert hydraulic formwork trolley, please click to visit:https://www.gf-bridge-tunnel.com/news/construction-technology-of-hydraulic-formwork-trolley-for-tunnel-invert/

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FULL ANALYSIS OF TUNNEL CONSTRUCTION METHODS

In the current tunnel construction practice, considering the construction cost and construction speed, the selection sequence of the construction method is: full-section method→step method→circular excavation method with core soil method→intermediate wall method (CD method)→cross middle wall method ( CRD method)→Double-side pilot pit method; from the perspective of construction safety, the order of selection should be reversed. How to make the right choice should be comprehensively considered based on the actual situation, but it must meet the requirements of safety, speed, quality and environmental protection, so as to achieve the purpose of avoiding risks, accelerating progress and saving investment.

1. FULL-FACE EXCAVATION METHOD

The full-section excavation method is a construction method in which the lining is constructed by blasting and forming at one time according to the designed contour.

Applicable conditions:

(1) The surrounding rock of Grade I to IV, when used in Grade IV surrounding rock, the surrounding rock shall have the conditions to maintain its own stability during the period from full-face excavation to the initial support.

(2) There are drilling rigs or self-made work benches and high-efficiency loading and transporting machinery and equipment.

(3) The length of the tunnel or construction section should not be too short. According to experience, it should not be less than 1km. Otherwise, large-scale mechanized construction is adopted, which is less economical.

The tunnel mechanized construction has three main lines of operation:

Excavation line: drilling trolley, charging trolley, loader with dump truck (trackless transportation), slag loading machine with mining car and battery car or diesel locomotive (tracked transportation).

Anchor shotcrete operation line: concrete injection machine, concrete injection manipulator, anchor shot operation platform, feeding and transportation equipment and bolt grouting equipment.

Moulding and lining work line: concrete mixing equipment, concrete truck and pump, waterproof layer working platform, lining steel mould trolley.

Construction features of full-face method:

(1) Excavation section and work space are large and interference is small;

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For more detailed information about tunnel construction methods, please click to visit:https://www.gf-bridge-tunnel.com/news/analysis-of-tunnel-construction-method/

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HOW TO CONTROL THE QUALITY OF TUNNEL LINING?

Tunnel lining plays an important role in the support of tunnel engineering. It is a permanent support structure built along the periphery of the tunnel body in order to prevent deformation or collapse of the surrounding rock. In actual construction, the quality control of the following links needs to be done. For details, please go to look down.

01. Lining construction

(1) The secondary lining must be carried out when the deformation of the surrounding rock and the initial support is basically stable, and the displacement convergence speed is obviously slowing down, and the various displacements must reach 80% to 90% of the estimated total displacement.

(2) Before the construction of the lining, the waist line must be measured to control the deviation of the invert and foundation pouring, and the lining section base surface and vault elevation should be detected. The thickness error of the tunnel lining meets the design requirements to ensure the clearance height in the tunnel.

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For more detailed information on how to control the quality of tunnel lining, please click to visit:https://www.gf-bridge-tunnel.com/news/how-to-control-the-quality-of-tunnel-lining/

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INTRODUCTION OF SAFETY TECHNOLOGY FOR LINING TROLLEY

Lining trolley is a large non-standard mechanical equipment used for secondary lining in tunnel construction. Its main structure is a steel structure combined with plate and beam. It is widely used in the construction of railways, highways and water conservancy and hydropower projects. It is difficult to analyze and calculate the strength and rigidity of its various components and the whole by using traditional mechanical design methods. Therefore, it is necessary to use the safety of the main lining trolley.

1. All formwork trolley operators must pass the safety training examination before they can work.

2. The trolley power supply control distribution box should be placed on the base of the tunnel, and it is strictly forbidden to control the power distribution of the trolley.The box is installed on the trolley, the power cord of the trolley must pass through the leakage switch, and the leakage action of the switch, the current should not be greater than 30mA, the leakage action time should not be greater than 0.1S, and the trolley cable should not there are joints, and the trolley should be reliably grounded.

3. Low-voltage lighting must be used on the lining trolley, and all power lines passing through the formwork trolley, often the lighting line and the template trolley should have insulation facilities, and the electrical line should be suspended, and power is prohibited lines, commonly used lighting lines are placed directly on the ground, or tied to the formwork trolley components,even immersed in water, electric lines that cannot reach a safe distance should be covered when firing the gun.

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For detailed information about the safety technology of the lining trolley, please click to visit:https://www.gf-bridge-tunnel.com/news/safety-technology-for-the-use-of-lining-trolley/

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INTRODUCTION TO THE SOFT LAP TECHNOLOGY OF TUNNEL LINING TROLLEY

In order to solve the problem of cracking of tunnel construction joints and the frequently-appearing handover acceptance problem, various construction units have paid a great price to solve this problem. If there is a way to effectively effect the newly poured second lining end during the construction process Protection not only saves a lot of cost, but also improves the quality of the secondary lining to a large extent. Today we introduce in detail a flexible joint device to protect the concrete at the end of the second lining, the soft lap technology of the tunnel lining trolley.

THE DAMAGE OF TRADITIONAL RIGID JOINT TO THE END OF THE SECOND LINER

In the secondary lining formwork trolley processing of the tunnel, limited by the factory production conditions and processing accuracy, the contour accuracy of the panels at both ends is not high and cannot be exactly the same, resulting in the slippage of the formwork trolley, due to the forming of the front panel of the formwork trolley There is a difference in shape between the concrete structure surface and the rear-end trolley panel, which cannot be completely coupled. In addition, the concrete pouring process cannot be consistent with the theoretical model. As the number of uses increases, irregular deformations of the formwork trolley panels will be difficult to correct, which will make the coupling problem more serious.

Therefore, during the construction overlap of the front and rear linings, there is a direct topping of the concrete at the overlap due to fear of leakage and tightening of the poured concrete surface, or invisible cracks in the concrete on the early pouring side of the construction joint that cannot be recognized by the naked eye. , During operation, it will fall under the action of the piston pressure difference formed by the high-speed train, jeopardizing driving safety. Moreover, due to the different causes and locations of the arch, the arch has the characteristics of “concealment, suddenness, complexity, and repeatability”. It is a relatively large source of danger for operating tunnels and must be completely eradicated. This problem is currently an important item of lining defects.

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For more detailed information about the introduction of soft lap technology of tunnel lining trolley, please click to visit:https://www.gf-bridge-tunnel.com/news/soft-overlap-technology-of-tunnel-lining-trolley/

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WHAT ARE THE FACTORS THAT AFFECT THE CURING EFFECT OF TUNNEL LINING CONCRETE?

The tunnel lining concrete maintenance can be divided into two types in terms of technology: water spray maintenance, spray maintenance and curing agent maintenance. Sprinkler maintenance refers to the use of water pipes or sprinklers to directly spray the maintenance water onto the concrete surface for maintenance, which can be operated manually or by spraying the lining trolley. Spray curing refers to the method of using atomizing equipment to atomize the curing water and then curing the concrete.

Manual sprinkling maintenance has low requirements for equipment, but the frequency, amount and duration of sprinkling water are subjective. Since the spraying trolley is carried out in a non-enclosed space in the tunnel, a large amount of maintenance water is retained and lost in the air when it is sprayed.

Although the curing agent can form a relatively complete film with isolation on the surface of the concrete, it is difficult to achieve a uniform ideal state in the spraying effect; at the same time, as the organic matter continues to volatilize, due to the inevitable uneven spraying, Weak areas will be formed in the areas where the spraying is thinner, and the concrete in these weak areas will undergo internal and external moisture migration and evaporation loss.

FACTORS AFFECTING CONCRETE CURING EFFECT

Cement concrete refers to the artificial stone formed by mixing water, aggregate and cement and then hardening after hydration reaction. Cement is a hydraulic cementing material. With the participation of water, new cementing compounds are formed, and then slowly harden into cement stone. This process is called hydration. However, after the concrete is poured, due to the humidity difference between the concrete and the air, the moisture inside the concrete has to evaporate and migrate to the external environment through the surface, thereby affecting the moisture required for the hydration of the concrete itself.

In order for the concrete hydration reaction to proceed normally, after the concrete is poured, it is necessary to maintain a temperature and humidity environment conducive to the cement hydration reaction for a considerable period of time. The curing of concrete is to create a curing measure that is conducive to the hydration reaction of cement. In addition, higher-quality concrete also requires good curing conditions in the early stage of hardening.

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For more information about the factors that affect the effect of tunnel lining concrete maintenance, please click to visit:https://www.gf-bridge-tunnel.com/news/factors-affecting-concrete-curing-effect/

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ANALYSIS ON THE QUALITY CONTROL IN THE SECONDARY LINING CONSTRUCTION OF THE TUNNEL

During the construction of the secondary lining of the tunnel, lining materials, concrete mix ratios and construction methods should be selected reasonably, and construction experience should be constantly summed up, and the quality awareness of relevant personnel should be improved, and the surface defects of concrete should be controlled to ensure the quality of the project so as to achieve good social benefits and Economic benefits.

The tunnel lining structure can be roughly divided into five processes: tunnel bottom (foundation) treatment, base surface treatment, waterproof material laying, concrete lining, and polyurethane mortar jointing. During the construction process, quality control is mainly done in the following aspects:

1. The bottom of the tunnel is the foundation of the lining structure. If it is loose and not strong enough, the lining structure is prone to settlement and deformation, and the foundation surface is flat. It is the key to ensure the accuracy of the elevation and the elevation error to meet the specification requirements and ensure the realization of the design longitudinal slope. Therefore, the construction process In accordance with the design requirements, do the initial support. When there is no initial support, the flatness and compaction quality of the foundation surface should be removed to remove the scum to ensure that the foundation surface is solid and flat.

2. Base surface treatment is a key process for waterproofing. Monitoring and measurement analysis believes that after the surrounding rock and initial support deformation become stable, cut sharp objects on the surface, remove hard objects, fill up unevenness, and ensure that the base surface is flat The degree meets the specification requirements.

3. The protection and laying of waterproof materials is the quality focus in the construction process. Impervious materials are transported by special vehicles to avoid damage during transportation. After entering the field, check the geometric size, thickness, and strength for holes, pinholes, and flaws. The construction site is welded by professional and technical personnel of the factory using special tools. After the welding is completed, the quality of the weld is checked, whether there is any de-welding or missing welding, and each weld is checked for air inflation. The welding is required to be dense, wheel marks obvious, straight, and free. Wrinkles and waterproof materials are forbidden to step on, slip, slide, and walk, so as to avoid puncture damage to the plastic film. The waterproof board should be protected during the construction of the steel bar project, and the small damage detected before laying and concrete lining should be welded in time with a hand welding gun or repaired as required.

4. Measure before moving the lining trolley to ensure that the center line of the steel mold lining trolley is consistent with the center line of the tunnel, and the arch wall template is fixed after positioning, and the measurement is reviewed. Clean up debris, stagnant water and floating ballast at the foot of the wall, install a steel stopper template at the front end of the lining trolley, and install and fix the waterstop according to the design requirements; remove the waterstop protection mold at the construction joints of the upper group of lining concrete and conduct self-inspection Waterproof system settings.

5. The smoothness and cleanliness of the console car surface during the lining construction ensures the overall appearance quality of the tunnel surface.

MAIN FACTORS AFFECTING THE QUALITY OF SECONDARY LINING CONSTRUCTION

1. IRREGULAR CONSTRUCTION PROCESS OR ON-SITE OPERATION

(1) The tunnel excavation is poorly formed and the lining concrete thickness is seriously uneven; under-excavation or initial support invades the lining boundary, resulting in insufficient lining concrete thickness; there is void behind the concrete lining of individual tunnels.

(2) The monitoring and measurement work was not carried out, and the construction time of the secondary lining was determined based on experience only. The safety and reliability were poor, which caused the secondary lining to bear the surrounding rock pressure beyond the design load.

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For more detailed information about the quality control analysis of the secondary lining construction of the tunnel, please click to visit:https://www.gf-bridge-tunnel.com/news/quality-control-in-the-construction-of-the-secondary-lining-of-the-tunnel/

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THE CRACKS IN THE LINING OF EXPRESSWAY TUNNELS AND THE TREATMENT MEASURES

Because natural conditions, geological environment, climate conditions, etc. are relatively complex and changeable, the construction difficulty of highway engineering is increased to a large extent. Tunnel engineering is a particularly important project in expressway construction. In recent years, as expressway construction extends to mountainous areas, the number of tunnel projects has also increased greatly. Tunnel construction has a certain degree of danger, concealment, and technology, so it is easy to encounter various technical problems in the process of construction. In addition to being restricted by the technical level of tunnel design, management level, materials and other factors, highway tunnels are prone to various diseases, among which lining cracks are more common. Lining cracks and diseases will affect the quality of highway tunnels to a large extent. Therefore, it is necessary to pay more attention to the diseases. Only by analyzing and finding out the cause of the disease can we formulate more targeted remediation measures and realize effective treatment.

OVERVIEW OF LINING CRACKS

Lining cracks are a very common type of disease in highway operations. When a highway tunnel lining cracks, it is easy to cause water leakage in existing tunnels. If the cracks are serious, it may even cause a sharp drop in the bearing capacity of the highway tunnel structure. Caused the road tunnel instability, collapse and other safety accidents. It can be seen that lining cracks are prone to have many adverse effects on highway tunnels. The distribution of lining cracks is more diversified, such as vertical cracks, longitudinal cracks, diagonal cracks, combined cracks and so on. Different lining cracks in different distribution patterns require different treatment methods. In order to achieve a better control effect, it is necessary to have a full understanding of the different distribution patterns of cracks.

Vertical cracks mainly refer to vertical axis cracks that occur in highway tunnels. The distribution of cracks occurs more in construction joints, settlement joints and the junctions of different addresses. For example, vertical cracks are prone to occur in the middle part of each slab molded concrete. Vertical cracks generally start from the bottom of the side wall, and continue to the end of the arch waist. The cracks are basically symmetrical at the left and right side walls, and some of the cracks will extend upward until they meet the vault. Longitudinal cracks mostly occur in the part of the tunnel vault and arch waist. Relatively speaking, the number of longitudinal cracks is less than the number of vertical cracks, but the harmfulness of longitudinal cracks is greater than that of vertical cracks. With the further development of longitudinal cracks, it is very likely that the tunnel lining will break or even collapse.

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For detailed information about cracks in the lining of highway tunnels and treatment measures, please click to visit:https://www.gf-bridge-tunnel.com/news/the-cracks-in-the-lining-of-expressway-tunnels-and-the-treatment-measures/

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MAINTENANCE SKILLS OF TUNNEL LINING WALKING SYSTEM

The maintenance of the walking system of the tunnel lining trolley mainly includes timely cleaning and cleaning, maintaining the tire pressure and track tension, and checking the front wheel positioning and operating conditions

For more information on the maintenance techniques of the tunnel lining trolley walking system, please click to visit:https://www.gf-bridge-tunnel.com/news/maintenance-skills-of-tunnel-lining-walking-system/

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DESIGN AND USE OF TUNNEL LINING TROLLEY

https://www.gf-bridge-tunnel.com/news/design-and-use-of-tunnel-lining-trolley/In the process of tunnel construction, the use of concrete for secondary lining is a very important work, and with the development of the times, there are new requirements for concrete secondary lining work, requiring higher quality and shorter construction period. Under the current trend, a good design of lining trolley has become an inevitable requirement.

TUNNEL LINING TROLLEY AND ITS REQUIREMENTS

The lining trolley is a special equipment that must be used in the secondary lining of the tunnel construction process, and is used for the concrete lining construction of the inner wall of the tunnel. Concrete lining trolley is an indispensable non-standard product for secondary lining during tunnel construction. There are mainly simple lining trolleys, fully hydraulic automatic walking lining trolleys and net-frame lining trolleys. Full hydraulic lining trolley can be divided into side-top arch type, full circle needle beam type, bottom mold needle beam type, full circle travel type and so on.

GENERAL REQUIREMENTS FOR TUNNEL LINING TROLLEYS

(1) The external dimensions of the formwork must be able to meet the requirements of the tunnel section. The shape error requirements are as follows: when ≤3m, not more than 10mm, when R>3m, not more than 20mm (R refers to the maximum section radius at the tunnel section).

(2) It must be ensured that the center of the formwork coincides with the center line of the tunnel. Therefore, the template can move left and right (that is, horizontally) when the main frame of the trolley does not shift laterally. Generally, the horizontal movement distance does not exceed 150mm from the centerline.

(3) The action of the template must be able to effectively complete the mold supporting, mold dismantling, and locking and positioning work. In the template trolley designed in recent years, the support and demolding of the template are hydraulically driven, and the locking is completed by mechanical devices. The overall formwork should be left with operating windows and grouting holes to meet construction requirements. The length of the overall formwork and the wheelbase of the gantry traveling wheels are related to the turning radius of the tunnel and the construction organization of other supporting machinery. The general formwork length is 6m ~ 12m, and the gantry axis distance is less than about 1m of the entire formwork length.

For more detailed information on the design and use of tunnel lining trolleys, please click to visit:

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DISASSEMBLY, ASSEMBLY AND USE CHARACTERISTICS OF TUNNEL INVERT TRESTLE

Tunnel invert construction has always been an important factor affecting construction progress and quality control. In order to reduce the interference of invert construction on slag loading and slagging machine and tunnel lining trolley, and to achieve the goal of accelerating the construction progress of mechanized parallel operation, high The fully-automatically controlled and fully hydraulic inverted arch trestle produced by GaoFei company has the following characteristics.

1) Modular assembly structure: The hydraulic inverted arch trestle adopts a plate-beam structure, which can be assembled quickly and modularly, and realizes the characteristics of variable span and convenient transportation.

2) Cantilever mobile structure: The trestle has a front cantilever, and the whole machine can be cantilevered. It has the function of retreating across the pit, effectively avoiding the impact of the face of the tunnel and the inverted blasting flying rocks. The trestle bridge can be crossed or withdrawn from the invert construction area at any time according to the technological requirements of the tunnel construction operation.

3) Full hydraulic drive mode: The whole machine of the trestle bridge adopts hydraulic drive or crawler walking. It has the characteristics of flexible control, simple structure, low noise, stable and reliable performance, and convenient maintenance and repair.

4) Sliding shoe walking method: The trestle adopts a sliding shoe walking method, which has the advantages of compact structure, small footprint, no noise, and stable and reliable walking. Among them, the selected high-performance wear-resistant materials have long service life. , Maintenance and repair are simple and other features. Of course, the crawler chassis is even more advanced.

5) Fully automatic control system: The trestle introduces a fully automatic PLC control system, which uses microcomputer operation to realize fully automated walking, which greatly facilitates driving operations.

6) High construction safety: The overall structure of the hydraulic inverted arch trestle is novel and reasonable in design, with large bearing capacity, stable structure and safety and reliability, which provides safety guarantee for construction vehicles and operators.

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