LanHi & Tunnel construction

　　As a key equipment for concrete spraying operations, the daily cleaning and maintenance of the wet spraying trolley is essential to ensure construction efficiency and equipment life. The correct cleaning steps can not only effectively remove the residual concrete, but also avoid pipe blockage and ensure the normal operation of the equipment. The following is a comprehensive wet spraying trolley cleaning process, which aims to help operators quickly master cleaning skills and improve work efficiency.

　　I. Cleaning steps after the operation

　　1. Pipeline and pump hopper cleaning: After the work is completed, start the cleaning procedure immediately. First, clean all pipelines and pump hoppers and piston cylinders to prevent concrete hardening and blockage.

　　2. Pump hopper cleaning: Open the lower door of the pump hopper and thoroughly remove the concrete residue in the hopper. Then, close the lower door, fill it with water, insert the cleaning ball into the pipe, and start the pump until the cleaning ball and clean water flow out to ensure that the interior is clean and free of residue.

　　3. Pipeline disassembly and cleaning: Remove all pipelines and rinse thoroughly with water until the water flow is clear to ensure that the inside of the pipeline is clean and unblocked.

　　4. Nozzle and pipeline cleaning: Design an end cap that matches the size of the nozzle and put it on the front end of the pipeline as a plug. Disassemble the connecting elbow, open the air source, and use compressed air to spray the concrete in the pipeline from the front end. At the same time, add water and cleaning balls into the pipe, and rinse repeatedly to ensure that there are no staff around to avoid safety risks.

　　5. Discharge port and S swing pipe cleaning: Open the discharge door, rinse with water, start the reverse pump switch, rinse the discharge port with water, and ensure that the pump S swing pipe is clean to avoid residues affecting the next use.

　　II. Cleaning tips

　　· Regular inspection: Regularly check the wear of the pipeline and pump, and replace the worn parts in time to avoid losing the big because of the small.

　　· Use special cleaning agent: On the basis of water washing, the use of special cleaning agent can more thoroughly remove concrete residues and reduce the number of cleaning times.

　　· Safety first: Before any cleaning operation, confirm that the equipment has been powered off to ensure the safety of the operator.

　　Through the above cleaning process, not only can the service life of the wet spraying trolley be extended, but also the construction efficiency can be improved and the failure rate can be reduced. Regular maintenance and cleaning are important links in equipment management that cannot be ignored.

　　Choosing the right water-cement ratio is one of the key technical points in the construction of sprayed concrete, which directly affects the fluidity, adhesion, strength and final construction effect of concrete. The following aspects should be considered to reasonably determine the water-cement ratio:

　　1. Design requirements: First of all, the design documents and relevant specifications of the project should be followed to clarify the expected strength grade and other performance indicators of the concrete, which is the basis for selecting the water-cement ratio.

　　2. Construction conditions:

　　- Type of spraying equipment: Different spraying equipment has different requirements for the rheological properties of concrete. Some equipment may be more suitable for thinner (higher water-cement ratio) concrete, while others are suitable for thicker (lower water-cement ratio).

　　- Spraying height and distance: When spraying over long distances or at high altitudes, a higher water-cement ratio may be more helpful in maintaining the fluidity of concrete and facilitate long-distance transmission.

　　- Spraying area shape: Spraying on complex curved surfaces or narrow spaces may require higher viscosity (i.e., lower water-cement ratio) to help the concrete fit and hang on the wall better.

　　3. Raw material properties:

　　- Aggregate type, particle size and gradation;

　　- Cement type. Different types of cement have different water absorption and different requirements for water-cement ratio;

　　- The influence of admixtures, especially plasticizers and water reducers, can significantly change the workability and strength performance of concrete.

　　4. Experimental verification: In addition to theoretical calculations and design guidance, trial mixing before actual construction is a very necessary step. By making test blocks, their physical and mechanical properties, such as compressive strength and elastic modulus, are measured, and the construction performance of concrete, such as slump, cohesion and water retention, are observed at the same time, which is used as an important basis for adjusting the water-cement ratio.

　　5. Site conditions: Taking into account environmental factors such as temperature and humidity on the day of construction, changes in these natural conditions will affect the initial setting time and hardening speed of concrete, and thus affect the choice of water-cement ratio.

　　6. Safety considerations: Safety is always the primary principle, especially in spraying operations. Although too high a water-cement ratio improves the fluidity of concrete, it may sacrifice long-term structural stability and safety.

　　In summary, choosing the right water-cement ratio requires comprehensive consideration of many factors, and the most suitable ratio is determined through scientific calculations, laboratory tests, and rich practical experience. In addition, continuous on-site monitoring and timely fine-tuning are also indispensable to ensure the quality of shotcrete construction.

　　What is the dark excavation method? The dark excavation method, also known as the tunneling method or underground excavation method, refers to a construction method that uses special equipment to dig and support underground without damaging the ground. It occupies an important position in urban underground projects, especially in areas with heavy traffic and dense buildings.

　　Advantages

　　1. Little impact on ground traffic and surrounding environment: The dark excavation method does not require large-scale excavation of the ground during construction, which can effectively reduce the impact on ground traffic, especially suitable for areas with heavy traffic such as urban centers.

　　2. Avoid large-scale demolition and pipeline relocation: Since there is no need for large-scale excavation of the ground, the dark excavation method can avoid disturbance of ground buildings and underground pipelines, and reduce the need for demolition and pipeline relocation.

　　Disadvantages

　　1. Difficult construction: The dark excavation method requires a high level of technology and precise construction operations, and has high requirements for construction personnel and equipment.

　　2. High construction risk: Underground construction has a large risk of stratum deformation, which requires precise control and monitoring to avoid ground collapse or other accidents.

　　3. High cost and slow construction speed: Compared with other construction methods, the construction speed of the dark excavation method is relatively slow and the project cost is also high.

　　Common dark excavation methods

　　1. Mining method: Excavation is carried out by drilling and blasting, which is suitable for various geological conditions. The flexibility of the mining method allows it to be used freely under complex geological conditions.

　　2. Shield method: The shield machine is used for excavation and lining construction, which is suitable for soft soil layers. The shield method has a high degree of mechanization and high construction efficiency.

　　3. Pipe jacking method: It is often used for the laying of small-diameter pipelines, and the pipeline is pushed by the pipe jacking machine. The pipe jacking method is suitable for short-distance and small-diameter pipeline construction, and the ground is less disturbed during the construction process.

　　As a construction method widely used in urban underground projects, the dark excavation method has many unique advantages, but it also faces many challenges. Reasonable selection and application of different types of dark excavation methods can effectively improve construction efficiency, reduce the impact on the environment and traffic, and achieve the smooth progress of the project.

　　Regarding the difference between the construction process of shotcrete lining and open cut method, we must first understand the construction process of the two, and then compare them.

　　I. Construction process of shotcrete lining

　　Shotcrete lining is usually constructed using the New Austrian Tunneling Method (NATM), and its construction process mainly includes the following steps:

　　1. Excavation: Use drilling and blasting method, tunnel boring machine method or other suitable excavation methods to excavate the tunnel according to the designed section size.

　　2. Initial support: Initial support is carried out immediately after excavation, including spraying concrete, installing anchor rods and steel mesh to control the deformation of the surrounding rock and ensure construction safety.

　　3. Monitoring and feedback: By installing monitoring instruments, the deformation of the surrounding rock and support structure is continuously monitored, and the construction parameters are adjusted according to the monitoring data to ensure support safety.

　　4. Secondary lining: After the initial support is stable, the secondary lining is applied according to the geological conditions and design requirements to form a composite lining structure to enhance the overall stability and waterproof performance of the tunnel.

　　5. Waterproof layer construction: Lay a waterproof layer on the inner side of the secondary lining to prevent groundwater penetration and protect the lining structure.

　　6. Installation of auxiliary facilities: Including the installation of drainage, ventilation, lighting, monitoring and other systems to improve the tunnel function.

　　II. Open-cut construction process

　　The open-cut construction process is relatively direct, mainly including:

　　1. Ground preparation: Clear ground obstacles, carry out fencing and traffic diversion in the construction area to ensure construction safety.

　　2. Excavation: Use excavators, bulldozers and other equipment to excavate from the ground to the designed depth to form a foundation pit.

　　3. Support: During or after the excavation, support is carried out, including piling, grouting, and support installation to prevent the collapse of the foundation pit.

　　4. Waterproof layer construction: Lay a waterproof layer on the bottom and side walls of the foundation pit to prevent groundwater penetration.

　　5. Underground structure construction: Pour concrete in the foundation pit and construct the underground structure, including the bottom plate, side wall and top plate.

　　6. Backfill and restoration: After the construction of underground structure is completed, the foundation pit is backfilled and the ground is restored, including roads, greening, etc.

　　III. The main differences between shotcrete lining and open cut method in the construction process are:

　　1. Excavation and support method: shotcrete lining is supported immediately after excavation, while open cut method is supported after excavation.

　　2. Construction environment: shotcrete lining is suitable for underground excavation, while open cut method is carried out on the ground.

　　3. Construction sequence: shotcrete lining is a dynamic construction, and the construction strategy is adjusted according to the monitoring data; the open cut method has a more fixed sequence, from ground excavation to underground structure construction.

　　These differences reflect the applicable scenarios and characteristics of the two construction methods. The choice of which method should be based on the geological conditions, environmental requirements and cost-benefit analysis of the specific project.

　　How does a rock drilling rig work? The working principle of a rock drilling rig is to drill holes in various directions at any part of the tunnel section through the mutual cooperation of the thruster, drill arm, slewing mechanism and translation mechanism. Specifically, the working principle of a rock drilling rig is as follows:

　　1. Thruster: When preparing to drill a hole, it enables the rock drill to quickly drive toward (or retreat from) the working face, and gives the rock drill a certain axial thrust when drilling. The operation of the thruster should be reversible, and the axial thrust and propulsion speed it generates should be adjustable at will so that the rock drill can work under the optimal axial thrust state.

　　2. Drill arm: It is the working arm that supports the rock drill. Its structure and size, flexibility and reliability of movement, etc. will affect the scope of application and production capacity of the rock drilling rig. The movement mode of the drill arm is rectangular coordinate type. The swing arm cylinder can be used to swing the swivel sleeve and the drill arm and the support arm cylinder hinged thereon around the axis of the swivel column left and right; the support arm cylinder can be used to swing the drill arm up and down around the hinge point, so that the propeller hinged to the front end of the drill arm can be used to swing up and down and left and right.

　　3. Rotation mechanism: It can be mainly divided into swing type swivel column, spiral sub-type swivel column, and polar coordinate drill arm rotation mechanism. The structural feature of the swing type swivel column is that there is a rotatable sleeve outside the swivel column shaft. The lower end of the drill arm and the lower hinge of the support arm cylinder are respectively hinged to the sleeve, and the swing arm cylinder is used to swing the sleeve around the swivel column, thereby driving the drill arm to swing left and right.

　　4. Translation mechanism: Through the hydraulic translation mechanism, parallel drilling holes can be obtained. When the pitch cylinder and the swing angle cylinder are controlled separately, inclined holes with a certain angle can be drilled. The propeller is flipped around the axis of the cylinder by flipping the cylinder to obtain drilling holes close to the sides and bottom of the tunnel.

　　When the rock drilling rig is working, it first pushes the rock drill toward the working surface through the thruster, and then adjusts the position and angle of the rock drill through the drill arm and the slewing mechanism to align it with the drilling position. Then, the rock drill starts to work and drills holes in the rock through impact and slewing movements. During the drilling process, the flushing mechanism will continuously inject water or air into the borehole to remove rock chips and dust in the borehole. Finally, when the drilling is completed, the rock drilling rig will withdraw the rock drill from the borehole and move to the next drilling position to start a new drilling operation.

　　Tunnel boring machines (TBMs) play an important role in modern infrastructure construction. As engineering conditions become increasingly complex, traditional hard rock TBMs and slurry balance TBMs are difficult to cope with the changing geological environment. The birth of hybrid TBMs provides a more flexible and efficient solution for tunnel excavation projects. It combines the advantages of two types of TBMs and can freely switch working modes under different geological conditions such as hard rock and soft rock, greatly improving construction efficiency and safety. Let's take a closer look at the technical characteristics, advantages and wide application scenarios of hybrid TBMs.

　　I. Core features of hybrid TBMs

　　The design concept of hybrid TBMs is to combine the advantages of hard rock TBMs and slurry balance TBMs, and achieve high adaptability to a variety of geological conditions through innovative modular design. The following are its main features:

　　1. Multifunctional cutting head: Equipped with an adjustable cutting head, it can freely switch working modes between hard rock and soft soil to ensure efficient and safe crossing of different geological layers.

　　2. Flexible propulsion system: With highly adaptable main drive and propulsion mechanism, it can maintain stable excavation speed and direction control even in complex underground environments.

　　3. Efficient support mechanism: With intelligent control system, it can automatically adjust the support strength according to the real-time monitored geological data, effectively maintaining the safety and stability of the tunnel structure.

　　4. Accurate guidance control: Integrating advanced navigation and positioning technology to ensure that the tunnel is excavated accurately along the predetermined route, reduce deviations and heavy work, and improve overall engineering efficiency.

　　II. Scope of application and application scenarios

　　Due to its excellent performance, the composite TBM has shown irreplaceable value in the following fields:

　　1. Complex and changeable geological conditions

　　In tunnel projects with frequently changing geological conditions, such as projects that need to cross multiple rock formations or water-bearing formations, the composite TBM can quickly switch working modes according to different geology, greatly reducing the difficulty of construction.

　　2. Projects with alternating hard and soft rock

　　Some tunnel projects involve frequent switching between hard and soft rock, such as crossing mountains or mixed geological layers under cities. The composite TBM can easily cope with this challenge with its flexible cutting head design and propulsion system.

　　3. Construction that requires rapid adaptation to geological changes

　　In some specific tunnel projects, due to tight construction schedules or high uncertainty in geological conditions, the composite TBM can quickly adjust its working mode to ensure that the project progress is not delayed and improve construction efficiency. The strong environmental adaptability and flexibility of the composite TBM make it one of the preferred solutions.

　　The composite TBM has become an important tool in the field of tunneling with its high flexibility, strong geological adaptability and intelligent control system. Its emergence not only improves the efficiency of tunnel construction, but also provides a safer and more reliable solution for projects facing complex geological conditions.

　　In the field of infrastructure construction, the wet concrete spraying trolley is an important construction equipment, and its efficiency and stability are crucial to ensuring the quality and progress of the project. In order to ensure that the wet concrete spraying trolley is always in the best operating state, regular comprehensive and detailed inspections are essential. This article will introduce in detail the main inspection items that should be carried out when the wet concrete spraying trolley is shut down to help operators and maintenance teams to find and solve problems in time, extend the service life of the equipment, and improve work efficiency.

　　1. Core performance evaluation

　　The first task is to check the core performance of the wet concrete spraying machine to confirm whether the parameters meet the rated indicators provided by the manufacturer. This includes but is not limited to key data such as pumping pressure, injection speed, and nozzle discharge uniformity. By comparing the actual test results with the standard values, it is possible to quickly identify whether there is performance degradation or potential failure.

　　2. Metal structure integrity inspection

　　The integrity of the metal structure is the basis for ensuring the safe operation of the wet concrete spraying trolley. Carefully check whether there are any open welds, cracks, deformations, and severe rust. These damages not only affect the appearance, but more importantly, they may weaken the mechanical strength and increase the risk of accidents. Once a problem is found, reinforcement measures should be taken in time or damaged parts should be replaced.

　　3. Inspection of working devices and accessories

　　Perform comprehensive functional tests on the working devices of the concrete wet spraying machine, such as boom telescopic and rotating mechanisms, to ensure that they can operate stably and smoothly. At the same time, check whether all accessories (such as spray guns and hoses) are complete and intact, and whether the bolts of each connection are tightened in place. Any negligence of any detail may lead to a significant reduction in overall performance.

　　4. Appearance cleanliness and leakage detection

　　Keeping the surface of the equipment clean is not only a basic maintenance requirement, but also an effective means to prevent premature wear of internal components. During the inspection, pay attention to whether there is leakage of oil, gas or water. Any type of leakage will reduce equipment efficiency and even cause environmental pollution and safety hazards.

　　5. Health status of electrical system

　　For concrete wet spraying trolleys equipped with motor drive, attention must be paid to the health status of their electrical systems. Pay special attention to whether the contact between the carbon brush and the slip ring of the motor is tight, whether abnormal sounds are generated during operation, and whether there is leakage. In addition, the insulation resistance value is measured and recorded regularly to ensure that it meets the technical specifications in the manual to avoid safety accidents caused by electrical problems.

　　The shutdown inspection of the concrete wet spraying trolley is a systematic work, covering multiple levels from performance testing to appearance maintenance. Only when every link is taken seriously can the long-term stable operation of the equipment be truly achieved. By implementing the above inspection items one by one, not only can the safety level of the work site be improved, but also the unplanned downtime can be effectively reduced, bringing significant economic and social benefits to the entire construction project.

　　In the field of tunnel engineering, traditional dry spraying concrete technology is gradually being replaced by more advanced wet spraying technology. This innovation not only greatly improves construction efficiency and safety, but also significantly reduces production costs and environmental pollution, becoming an important driving force for industry transformation. Let's talk about the advantages of vehicle-mounted wet spraying machine trolleys and their far-reaching impact on the field of tunnel construction.

　　First, cost savings and significant benefits

　　The vehicle-mounted wet spraying machine trolley has greatly optimized the material handling process through its intelligent design and achieved accurate and efficient material supply. The hopper is equipped with an adjustable discharge speed gate, which can be flexibly adjusted according to the spraying speed, effectively preventing the waste of mixed materials and avoiding the material loss that may be caused by traditional manpower discharge. In addition, compared with the previous 8-10 workers required for heavy manual loading, now only 2-3 people can easily operate the wet spraying trolley, which greatly saves human resources. Especially in high-risk working environments, this change is of great significance, which not only improves the safety factor but also reduces labor costs.

　　2. High efficiency and low energy consumption, productivity leap

　　The vehicle-mounted wet spraying machine trolley has a large-capacity hopper and an intelligent hydraulic control system, which ensures a continuous and stable material supply, allowing the spraying machine to fully exert its efficiency and avoid frequent shutdowns to wait for materials. According to preliminary tests, after using the wet spraying machine trolley, the efficiency of the spraying operation has increased by about 30%. At the same time, due to the shortened working cycle and reduced overall energy consumption, statistics show that the power consumption on the construction site has decreased by about 35%, achieving a win-win situation of economic benefits and energy conservation.

　　3. Simple operation and wide application

　　The vehicle-mounted wet spraying machine trolley has a compact design, a friendly operation interface, and is easy to master. It is suitable for a variety of complex construction sites. Whether it is a small space or a rugged terrain, it can respond flexibly, showing extremely high adaptability and flexibility. This convenient operation feature further broadens its application scope in tunnels and other infrastructure construction projects.

　　4. Green construction, environmental protection

　　While improving construction efficiency, the vehicle-mounted wet spraying machine trolley is also committed to environmental protection. It effectively reduces the scattering and particle emissions of mixed materials during transportation and reduces dust pollution. More importantly, the problem of dust in the return air system was successfully eliminated through the transformation, contributing to creating a cleaner working environment.

　　In summary, the vehicle-mounted wet spraying machine trolley has become an indispensable key equipment for modern tunnel construction with its outstanding performance in cost control, efficiency improvement, operational convenience and environmental protection, leading the industry to a higher level.

　　What are the skills for wet spraying trolley spraying concrete construction? When wet spraying trolleys are performing spraying concrete construction, mastering the correct construction skills is crucial to improving work efficiency and ensuring project quality. Here are some key construction skills and precautions:

　　1. Accurate mix design

　　- Ensure the accurate ratio of cement, aggregate, water and admixtures, which directly affects the fluidity and final strength of concrete.

　　- Adjust the mix ratio according to site conditions, such as humidity, temperature changes and other factors.

　　2. Good material pretreatment

　　- Aggregates should be clean and dry, and avoid excessive dust or other impurities that affect the quality of concrete.

　　- For construction in humid environments, the amount of water should be appropriately reduced to maintain the optimal consistency of the mixture.

　　3. Control the spraying parameters

　　- Nozzle pressure: Too high will increase the rebound rate, and too low may cause the concrete to be loose. Find the ideal pressure value suitable for the current construction conditions.

　　- Distance and angle: Keeping the nozzle at an appropriate distance from the sprayed surface (usually about 0.6 to 1 meter) and at an appropriate angle (about 75° to 90°) helps reduce rebound and improve adhesion.

　　4. Spray continuously and evenly

　　- Spray as continuously as possible to avoid joint problems caused by pauses.

　　- Move the nozzle in a spiral or zigzag trajectory to ensure full coverage and uniform thickness.

　　5. Timely maintenance

　　- Start maintenance work immediately after spraying, especially early moisturizing maintenance is particularly important to prevent crack formation.

　　- The curing time depends on the specific climatic conditions and concrete type, but generally should not be less than 7 days.

　　6. Monitor rebound rate and dust emission

　　- A high rebound rate means a lot of material is wasted and the subsequent cleaning work is increased. Check the rebound regularly and adjust the process to reduce this rate.

　　- Take measures to reduce dust emissions, protect workers' health, and comply with local environmental regulations.

　　By following the above tips and precautions, you can greatly improve the effect of wet spraying trolley shotcrete construction and ensure the safety and durability of the structure. In addition, regular maintenance and care of the equipment is also an integral part of maintaining its optimal performance.

　　Whether in the plateau with thin oxygen or in the mountains and rivers with few people, where there are LANHI equipment, there are LANHI people

　　Recently, LANHI launched the "Crossing Mountains and Rivers, Service Accompanying, Satisfaction Traveling" 2024 Second Phase Visit Service Activity, going deep into the customer's use site, providing one-stop free service, solving problems for customers, and providing maintenance services for the entire life cycle of the equipment.

　　"Product sales are just the beginning of our service work. From production assembly, quality control inspection, to on-site commissioning, repair and maintenance, we are committed to providing full life cycle services for every "LANHI-made" and regularly conducting product quality inspections after sales to ensure that problems arising during equipment operation can be solved at any time." Zhang Qiang, head of LANHI's after-sales service department, said.

　　This inspection service lasted for 1 month. The LANHI After-Sales Service Center instructed the R&D, production, quality control, marketing and other horizontal departments to form an inspection team, and went to Qinghai, Gansu, Shaanxi, Tibet, Chongqing, Hubei, Guangxi, Guizhou and other regions to visit more than 110 customers, and actively served, inspected and maintained about 150 equipment. They drove deep into the front line of the project without fear of dawn and dusk, and conducted free "physical examinations" on the customer's equipment, covering equipment maintenance, on-site guidance, technical Q&A, maintenance and other full-service, to prevent and solve the hidden dangers and "pain points" in the use of equipment, etc., and demonstrated the quality and commitment of LANHI's service with practical actions.

　　Not only that, LANHI continues to strengthen the technical support team, and regularly conducts team course training and customer operator skills training for common practical problems of customers to ensure consistent service quality and win the trust and satisfaction of customers with professionalism and enthusiasm.

　　The service purpose of "creating greater value for partners" is not only an important part of LANHI's culture, but also the core force of LANHI in building strong customer connectivity and market competitiveness in the layout of high-end intelligent manufacturing industry. Since the launch of LANHI's "Service Thousand Miles" campaign in 2018, we have always put customer needs first, and continued to give back to customers' support and trust with more comprehensive and meticulous services, which has achieved good social effects and won high recognition from customers. We firmly believe that only by continuously creating greater value for our partners can we push the company towards a higher quality development path.