Lining trolley generally consists of template assembly, bracket assembly, translation mechanism, mast assembly, master-slave travel mechanism, lateral hydraulic cylinders, lateral support jacks, bracket support jacks, and gantry support jacks.

1. Template assembly

The template consists of 1~2 top molds and 2~4 side molds to form a cross section. The top mold and the top mold are connected as a whole by bolts, and the side mold and the top mold are connected by hinge trunnions. Each section of the template is made 1.5 meters wide, composed of multiple sections, and the templates are connected by bolts. There are working windows arranged in a product shape on the template, and a grouting device connected with the delivery pump Φ125 is installed on the top.

2. Bracket assembly

The bracket mainly bears the weight of the upper concrete and formwork during casting. It supports the formwork, and the lower part transmits the force to the mast through a hydraulic cylinder and a supporting jack. The bracket is composed of two longitudinal beams, two side beams, multiple middle beams and uprights. The longitudinal beams are welded by steel plates into an I-shaped section; the side beams and multiple middle beams are made of I-steel; the columns are made of I-steel.

3. Translation mechanism

A hydraulic trolley, one set of translation mechanism at the front and rear, is supported on the side beam of the mast. The hydraulic cylinder (GE160/90─300) on the translation trolley is connected to the bracket longitudinal beam, and the vertical positioning and demolding of the template are adjusted through the contraction of the cylinder. The adjustment stroke is 300mm; and the horizontal cylinder (GE90 /50─200) It is used to adjust whether the center of the lining of the template is aligned with the center of the tunnel. The left and right adjustable stroke is 100mm.

4. The door frame assembly

The mast is the main load-bearing component of the entire trolley. It is made up of beams, columns and longitudinal beams connected by bolts, and each beam and column are connected by connecting beams and diagonal tie rods. The main structure of the hydraulic trolley is welded by steel plates, and the entire mast is guaranteed to have sufficient strength, rigidity and stability. The mast beams are welded by steel plates into I or II-shaped cross-sections; the columns are also welded by I-beams into I or II-shaped cross-sections; the longitudinal beams are welded by steel plates; the oblique supports are made of I-beam or channel steel; each connecting beam adopts grooves Steel, I-beam or angle steel.

5. Master-slave walking mechanism

The hydraulic trolley has two master and slave walking mechanisms, which are hinged on the longitudinal beam of the mast. The main traveling mechanism is decelerated by a Y-type motor driven by a first-stage gear, and then decelerated by a two-stage chain. The traveling speed is 8m/min and the traveling wheel diameter is φ350mm;

6. Lateral hydraulic cylinder

The lateral hydraulic cylinder is mainly used for demolding the side template, and at the same time it plays the role of supporting the template. The lateral cylinder (GE100/63-400) selects 4 cylinders according to the length of the lining, and the adjustment stroke is 250mm.

7. Lateral screw jack

The screw jacks installed on the portal frame are used to support and adjust the position of the formwork and bear the pressure generated when concrete is poured. The screw diameter is 65mm, and its adjustment stroke is 250mm. Consider that the special screw of this trolley is a single screw.

8. Bracket supporting weight

It is mainly to improve the stress conditions of the bracket longitudinal beam when concrete is poured, and to ensure the reliability and stability of the bracket. The screw diameter is 65mm, and its adjustment stroke is 150mm.

9. The support of the door frame

It is connected under the longitudinal beam of the gantry. When the trolley is working, it bears the weight of the trolley and concrete, which improves the stress condition of the longitudinal beam of the gantry and ensures the stability of the gantry when the trolley is working. The screw diameter is 65mm and its adjustment stroke is 200mm.

The above is a detailed introduction of the various components of the lining trolley. Only by clearly grasping the working principle of each component can the lining trolley be better operated.

Tunnel trolley is a relatively common product on highways. The installation of tunnel lining trolleys is relatively complicated. First, choose the installation location, and then install the walking wheel frame assembly, various accessories, accessories and systems. And so on, but the installation of steel bars is more important in the entire installation and use process, because it is related to the subsequent use. Then, what are the installation requirements of the lining trolley, let’s take a closer look!

1) Each node of the transverse reinforcement and the longitudinal reinforcement should be tied or welded;

2) The welded lap length of the steel bar shall meet the design and specification requirements, the lap joint of the stressed main bar shall be welded, and the welded lap length and weld shall meet the requirements of the specification;

3) The overlapping positions of adjacent main bars should be staggered, and the staggered distance should not be less than 1000mm;

4) The two overlapping distances of the same stressed steel bar should not be less than 1500mm;

5) The connection point of the stirrup should be at the cross connection of the longitudinal and longitudinal ribs, and should be tied or welded;

6) Other connection methods of steel bars should comply with relevant specifications;

7) When installing steel bars, the length, spacing, position and thickness of the protective layer of the steel bars should meet the design requirements.

Reinforcing steel bars should be positioned according to the design outline. In order to ensure that the positioning of the secondary lining steel bars is accurate and the thickness of the steel protection layer meets the requirements, the following measures should be taken:

(1) First, the surveyor uses coordinates to set out the center points of the front and rear two steel bars within the scope of the self-made trolley on the leveling layer and the vault waterproof layer, and determine the normal direction to ensure the verticality and verticality of the positioning steel bars. The accuracy of the arch reserved steel connection. The verticality of steel tying is determined by the method of three-point hanging ball.

(2) Use a level to measure the elevation of the center point of the positioning steel bar on the leveling layer, calculate the height difference between the center of the mileage and the center point on the leveling layer, and use a self-made tripod to determine the center of the circle.

(3) After the center of the circle is determined, use the ruler method to check whether the size of the positioning steel bar meets the design requirements, re-adjust the positions that do not meet the requirements, and fix the steel bars after all meet the requirements. The steel bar is fixed by the adjustable support rod welded by steel pipe on the self-made trolley.

(4) After the positioning steel bars are fixed, use chalk to mark the location of the circumferential main reinforcing bars on the support rods according to the design steel bar spacing, mark the installation positions of the longitudinally distributed ribs on the positioning steel bars, and then start binding the steel bars within this section. The intersection of steel bars should be tied.

In short, the tunnel lining trolley manufacturer specially reminded that the steel protection layer should be controlled by high-strength mortar pads, and plastic pads should not be used. It is required that the longitudinal spacing of the main ribs, the circumferential spacing of the distributed ribs, the horizontal spacing of the inner and outer layers, and the thickness of the protective layer meet the design requirements.

During the secondary lining construction of the tunnel, the tunnel lining trolley is an indispensable professional equipment. The tunnel lining jumbo is generally designed as a steel arch type, which is mainly used in the construction of medium and long tunnels to improve construction efficiency. Then, in the actual operation process, what are the operating procedures and precautions for the tunnel lining trolley? Here is a brief introduction:

Operating procedures

1. Operator job requirements

① The operator should have received good safety technology and skill training. Work with a certificate.

② The operator shall do the inspection and maintenance of the daily use of the lining trolley, and make necessary records.

③ Strictly follow the technical explanations and the corresponding operating procedures.

2. Work preparation before operation

① After the assembling of the trolley is completed, each connecting screw shall be checked and tightened one by one, and it can be put into use after the joint inspection and acceptance by all parties.

② Wear belts when constructing on the trolley, and cover the operation area with 5cm wooden boards to prevent the operator from falling from a height. The two trolleys are equipped with eye-catching reflective strips.

3. Specific operating procedures

① The base surface of the trolley track should be solid and flat. It is strictly forbidden to have soft sides and hard sides. The top surface of the track should be on the same plane, and the track spacing should be consistent with the wheel flange of the trolley.

② The top surface of the trolley track is basically parallel to the longitudinal excavation surface of the tunnel. When the slope is large, a track clamp should be set at a place not less than 3m at the head of the track to prevent the trolley from derailing during operation.

③ When the trolley moves to its place, when the trolley slides down automatically, the operator should send people on both sides of the forward direction to check the operation at the same time. When an abnormal situation occurs, the operator should be notified at any time to brake the trolley immediately. When the trolley moves with external forces (loaders, excavators), a qualified wire rope must be used to drag the trolley along the uphill direction of the tunnel, and move slowly, allowing the trolley to move under its own gravity. It is strictly forbidden to follow the direction of the slope Go trolley.

④ The trolley should be moved slowly and smoothly. When it is difficult to move, carefully check whether there are hard objects stuck on the sides or bottom of the trolley. Check whether there are steel bars on both sides and the top surface that hinder the operation of the trolley. The trolley should be stopped to advance, and the steel frame may collapse easily.

⑤ After the trolley is positioned, the operator should first wedge the trolley wheel with a wooden wedge, and then perform the positioning adjustment of the trolley under the command of the surveyor. When the trolley has a large deviation, the cylinder should be adjusted symmetrically. The position of the trolley meets the balance requirement. When the positioning of the trolley meets the requirements, the screw jacks at the bottom of the trolley should be tightened first, and then the jacks on both sides of the trolley should be tightened symmetrically. When the tops of the screw jacks of the trolley are tightened in place, loosen the hydraulic cylinder jacks. Open to protect the cylinder.

⑥ Before pouring the concrete, the operator should repeatedly check the jacks one by one to ensure that each screw jack has been tightened, and the top of each hydraulic jack is depressurized. In the process of concrete pouring, it should be placed strictly symmetrically, and the height difference between the two sides of the mold concrete should not exceed 1 meter, preferably 0.5-0.8 meters, and someone should be sent to check the jack. When the molded concrete structure is thick and large in volume, the pouring speed should be slowed down in a timely manner, and the frequency of the mold should be checked closely to prevent accidents caused by running, rising, and collapse of the mold
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⑦ The power supply control box of the trolley should be placed on the base of the tunnel. It is strictly forbidden to install the control box on the trolley. All power cables must pass through a leakage protector. The operating current should not exceed 30 amperes and the operating time should not exceed 0.1 seconds. The cable must use rubber flexible cable, and there must be no joints or damage in the middle, and the trolley frame body must have a reliable protective zero connection.

⑧ The lighting on the trolley should use safe voltage or flashlight.

Other matters needing attention

1. When a vehicle passes under the trolley clearance during the construction period, a person should be assigned to conduct traffic command and management to prevent the vehicle from colliding with the trolley.

2. Strictly control the center line of the steel rail to avoid excessive deviation between the center of the backstage car and the center of the tunnel.

3. During the rail laying process, the rails must be firmly connected to each other to avoid crushing the rails or derailing the trolley due to the excessive weight of the trolley.

4. Remove the virtual ballast under the sleepers to avoid sinking due to the weight of the concrete and the trolley during the lining process.

5. The baffle plate bears a lot of force, and must be reinforced firmly during the erection process. During the concrete pouring process, it must be inspected and reinforced at any time.

6. The second lining concrete pouring takes a long time. In order to facilitate the simultaneous construction of the second lining and the ballast discharge, the delivery pump is placed far away from the lining trolley.

7. The concrete conveying pipe is firmly fixed on the bench, and the pipe should not be in contact with the template, so as to avoid strong vibration at the nozzle when the concrete is pressed out and the template will be deformed and run. The joint pipe clamp should be connected firmly to avoid bursting off, and the pipe shall be raised above the ground with square wood, and the pipe clamp shall not directly contact the trolley components when passing through the trolley.

Tunnel lining trolleys are widely used in the construction of concrete secondary lining of highways, railway tunnels and underground caverns due to their good performance, reasonable structure, and good lining quality. The above is a specific description of the operating rules and precautions of the tunnel lining trolley. I hope it can help everyone to have more understanding of the tunnel lining trolley. Luoyang Gaofei Bridge Tunnel Machinery Co., Ltd. has been specializing in the production and research and development of tunnel lining trolleys for many years. The series of products are spread all over the country and are well received by customers. Interested parties are welcome to consult.

Attention should be paid to the following points when excavating steps: With the implementation of information technology, the impact of tunnel construction on the surrounding environment has been minimized, and the construction efficiency has been greatly improved. Various integrated pipeline corridors, subway tunnels, and highway tunnels are constructed everywhere. It can be seen that, especially in subway and high-speed rail construction in recent years, various tunnel projects have emerged one after another, and there are more and more construction techniques and methods. The relevant personnel of tunnel construction manufacturers have summarized and shared 6 commonly used tunnel construction methods for us, let’s take a look. Right.

1. Full-face excavation method

The full-face excavation method is a construction method in which the lining is formed by blasting at one time according to the design contour.

Applicable conditions:

(1) I~IV class surrounding rock, when used in class IV surrounding rock, the surrounding rock should 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 shipping 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:

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

Anchor shotcreting line: concrete shotcrete machine, concrete shot manipulator, anchor shotcrete work 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 working space are large and interference is small;

(2) Conditions to make full use of machinery and reduce manpower;

(3) There are few procedures, which is convenient for construction organization and management, and improves working conditions;

(4) Excavation takes shape at one time, which has less disturbance to surrounding rock and is beneficial to the stability of surrounding rock.

2. Step method construction

The step method is to excavate the upper half of the section first, and after the excavation reaches a certain length, the lower half of the section is excavated at the same time, and the upper and lower half of the section are simultaneously advanced; according to the length of the step, there are three types of long steps, short steps and ultra-short steps. . In recent years, due to the design of large-section tunnels, there have been three-step temporary inversion methods and even multi-step methods.

As for which step method should be used in construction, it should be decided according to the following two conditions:

(1) The time required for the initial support to form a closed section. The worse the surrounding rock, the shorter the closing time.

(2) Requirements for the size of the construction site for the excavation, support, and ballasting of mechanical equipment used in the construction of the upper section.

In the weak surrounding rock, the former should be the main one, while the latter should be taken into consideration to ensure construction safety. When the surrounding rock conditions are better, the main consideration is how to better exert the mechanical efficiency and ensure the economic efficiency of construction, so only the latter condition is considered.

The advantages and disadvantages of the step excavation method:

The step excavation method can have enough working space and considerable construction speed. However, the upper and lower operations have interference; although step excavation increases the number of disturbances to the surrounding rock, the step is conducive to the stability of the excavation surface. Especially after the upper excavation and support, the lower operation is safer, but attention should be paid to the influence of the lower operation on the upper stability.

(1) Solve the problem of mutual interference between upper and lower half section operations. The micro steps are basically combined into a working face for simultaneous excavation; the long steps are basically opened, and the interference is small; while the short steps have greater interference, and attention should be paid to the work organization. For tunnels with a shorter length, the upper half of the section can be penetrated before the lower half of the section is constructed.

(2) When excavating the lower part, pay attention to the stability of the upper part. If the stability of the surrounding rock is good, it can be excavated in stages; if the stability of the surrounding rock is poor, the lower excavation cycle should be shortened; if the stability is worse, it can be staggered to the left and right, or the middle groove can be pulled first and then dig Side gang.

(3) After the excavation of the lower side wall, the concrete must be shot immediately, and the initial support must be made according to the regulations.

(4) The measurement work must be timely to observe the displacement value of the vault, the arch foot and the middle of the side wall. When the speed is found to increase, the invert arch should be closed immediately.

3. Ring excavation to retain core scholars

The following points should be paid attention to in the ring excavation and core soil method:

(1) The circular excavation footage should be 0.5-1.0m, and the core soil area should not be less than 50% of the entire section area.

(2) Spray anchor support and steel frame support should be constructed in time after excavation. Adjacent steel frames must be connected by steel bars, and the angle lock anchors should be designed and constructed according to construction requirements.

(3) When the surrounding rock geological conditions are poor and the self-stabilization time is short, advance support should be carried out according to the design requirements before excavation.

(4) The excavation of the core soil and the lower steps should be completed after the upper step support is completed, and the sprayed concrete reaches 70% of the design strength.

4. The next door method (CD method)

The CD method is a construction method in which one side of the tunnel is first excavated in a large-span tunnel with weak surrounding rock, and the middle side wall is constructed, and then the other side is excavated. It is mainly used in double-line tunnels with deep buried hard rock in the IV-level surrounding rock Lots and old loess tunnels (Class IV surrounding rock) lots.

5. Double side wall pilot pit method

The double-sided pilot pit method generally divides the section into four sections: the left and right side pilot pits, the upper core soil and the lower steps. The principle is to use two intermediate walls to divide the entire large section of the tunnel into three small sections on the left, middle and right for construction. The left and right pilot tunnels go first, and the middle section immediately follows; after the initial supporting inverted arch is formed into a ring, the two sides of the pilot are removed. The hole is temporarily supported to form a full section. The pilot holes on both sides are inverted oval-shaped, which is beneficial to control the sinking of the vault.

When the tunnel span is large, the surface subsidence requirements are strict, the surrounding rock conditions are particularly poor, and the single-side pilot method is difficult to control the surrounding rock deformation, the double-side pilot method can be used. Field measurements show that the surface subsidence caused by the double-side pilot method is only 1/2 of the short-step method. Although the double-wall pilot tunnel method has many excavation sections and large disturbances, it takes a long time to close the full section of the first support, but each section is closed immediately after excavation, so the deformation is almost Does not develop. The construction of the double-side pilot tunnel method is safe, but the speed is slow and the cost is higher. This method is mainly applicable to formations such as cohesive soil layer, sand layer and sand egg layer.

The construction sequence of the double-side pilot pit method is:

(1) Excavate a pilot pit on one side and close it for the first time in time.

(2) Excavate the pilot pit on the other side after a proper distance, and construct the primary support.

(3) Excavate the upper core soil to construct the primary support of the arch, and the arch foot is supported on the primary support of the pilot pit on both sides.

(4) Excavate the lower steps and construct the first support at the bottom, so that the full section of the first support is closed.

(5) Remove the first support of the empty part of the pilot pit.

(6) Construct the inner lining.

Pay attention to the following points in the double-sided pilot pit method:

(1) The next excavation can be carried out only after the sidewall pilot pit is excavated. When the geological conditions are poor, a temporary steel frame or temporary inverted arch should be installed at the bottom of each step according to the design requirements.

(2) When each part is excavated, the peripheral contour should be as smooth as possible.

(3) Excavation should be carried out on the other side after the strength of the shotcrete on the excavation side reaches the design requirements.

(4) The longitudinal spacing of the excavation face of the pilot pits on the left and right sides should not be less than 15 meters.

(5) When the excavation forms a full section, the initial support closure of the full section should be completed in time.

(6) The partition wall and temporary supports shall be removed section by section when the secondary lining is poured.

6. Fork in the next door method (CRD method)

Fork-in-the-next-wall method is to excavate one or two parts of one side of the tunnel in a large-span tunnel with weak surrounding rock, apply the partition and diaphragm in the part, and then excavate one or two parts on the other side of the tunnel to complete the horizontal Diaphragm construction; then excavate the last part of the first construction side, extend the middle wall, and finally excavate the remaining part. When the short-step method is difficult to ensure the stability of the tunnel face, the CRD method with a small section size should be used, which is more advantageous for controlling deformation.

The CD law is the abbreviation of “Center Diaphragm”, and the CRD law is the abbreviation of “Cross Diaphragm”. The two are both related and different. They are used in relatively weak stratum and are large section tunnels. The former is a method of excavating by dividing the partition with steel support and shotcrete; the latter is a method of using the partition and invert to divide the section up and down, left and right to excavate, and the geological conditions require the section section The method adopted under timely closed conditions. Therefore, the only difference between the CRD method and the CD method is that each step in the construction process requires the use of temporary inverts to close the section.

In the CRD method or the CD method, a key issue is the removal of the middle wall. Generally speaking, the middle wall should be removed only after the full section is closed and the displacement of each section is fully stabilized.