With the rapid growth of urban high-density development and underground space engineering, the difficulty of concrete pouring in narrow spaces, ultra-high-rise structures and complex shaped work surfaces has significantly exceeded the capacity boundary of traditional pumping equipment. As a special equipment to cope with such working conditions, the spider boom concrete pump is characterized by lightweight chassis, folding telescopic arm frame, and spider leg-like variable-amplitude legs as the core design features. It can complete high-precision, continuous and large-radius concrete pouring operations in a narrow site where traditional equipment cannot unfold.
Concrete pumping in narrow space does not refer to a single type of construction scenario, but covers a series of special operating environments limited by spatial conditions in urban construction projects. Its core characteristics are the multi-dimensional constraints of equipment entry path, operation development space and coverage, which cannot be completed by traditional pump trucks or fixed fabric machines. Pour into concrete. Concrete pumping operations in narrow spaces usually have the following typical characteristics.
The passage is narrow. It is difficult for construction vehicles and equipment to reach the operation surface directly, and it often takes many transshipments or even manual handling to transport materials and equipment to the designated location. In the streets and alleys of the old city, the width of the road is often only a few meters, and large transport vehicles cannot enter at all.
The operation area is limited. The space available for equipment arrangement, material storage and personnel activities is extremely cramped. There is almost no extra safety distance between the equipment and between the equipment and the structure, and any operating error may lead to collisions.
Equipment arrangement is limited. Large pump trucks and mixing equipment cannot enter or unfold, and a miniaturized and modular equipment scheme must be adopted. The traditional pump truck unfolding arm frame requires a flat area of at least 4 meters x 4 meters, and the minimum operating radius is more than 3 meters.
The surrounding environment is complicated. Small space construction is common in residential areas, commercial areas, historical and architectural protected areas or nature reserves, and the requirements for construction noise, vibration and environmental protection are extremely high. Any construction disturbance may cause complaints from surrounding residents, disputes over the protection of cultural relics or damage to the ecological environment.
In order to support the operation range of the long arm frame, the traditional concrete pump truck not only needs a large entry and passage space, but also needs to fully unfold the legs during operation in order to maintain the stability of the whole vehicle; under narrow space conditions, this basic condition is often not met, and the equipment may not be able to reach the designated operation point at all, or Even if you can enter the field, you can’t get enough space to unfold the arm frame and legs.
The narrow space operating environment fundamentally limits the layout design of concrete pumping pipelines and greatly increases the difficulty of pipeline arrangement. In conventional construction scenarios, pumping pipelines can be laid out along straight lines or large-angle curves to reduce the resistance of concrete during transportation as much as possible; however, under narrow space conditions, pipelines must bypass the on-site structural columns, rebar supports, existing pipelines and other obstacles, which often need to be arranged 90° or even smaller. Angle bends, the turning radius of the pipeline of some projects is even less than 1 meter.
Under narrow space conditions, the technical defects of the traditional fabric method will be further amplified by the complex operating environment. For this kind of construction scenario, the quality control difficulties of concrete pouring are mainly concentrated in three links. First of all, it is difficult to guarantee the continuity of pouring, secondly, the fabric accuracy of the equipment is insufficient, and finally, it is difficult to coordinate the supply of concrete.
Narrow space construction scenarios are often located in the core area of the city, or there is multi-process cross-operation on the site. The contradictions between personnel, machinery and sites are highly concentrated, and the probability of safety risks is much higher than that of conventional construction scenarios. The first is the stability risk of the equipment itself. The spread area of the legs of traditional pumping equipment is large, and the ground conditions in a narrow space often cannot meet the stable support requirements of the legs; secondly, there is the risk of cross-operation between personnel and machinery. Under narrow space conditions, the operating rotation radius of the equipment often overlaps with other operating areas on the site; if the fixed strength of the pipeline is insufficient, or the sealing at the joint is defective, the problem of pipe cracking and concrete splashing may occur, which directly threatens the personal safety of the on-site construction personnel.
In the narrow space construction scenario, the transfer and in-place efficiency of the equipment are the key factors affecting the overall construction period of the project. Even if some traditional equipment can complete the pouring operation, if it takes a lot of time on site cleaning, equipment in place, transfer and other links, it will also seriously affect the development of subsequent processes. It can be said that under such limited space conditions, if traditional pumping equipment is still used, even if a large amount of labor cost investment is increased, the construction quality, efficiency and safety cannot be fully guaranteed.
The spider boom is a special concrete pouring equipment specially developed to adapt to construction scenarios in which traditional pumping equipment cannot operate in narrow spaces, complex terrain and other areas. Its core design logic is to greatly reduce the floor area of the fuselage through structural optimization under the premise of retaining the operating capacity of the traditional fabric machine. And the volume after convergence. The core structural feature of this kind of equipment is the adoption of H-type or X-type hydraulic legs similar to spider legs. This kind of legs can be adjusted separately according to the actual spatial conditions of the operating surface to provide sufficient support and stability for the equipment.
This is the core premise that the spider arm frame can replace traditional equipment under narrow space conditions. In the operation support link, the design of its spider hydraulic legs further improves the adaptability to narrow sites – the legs of the traditional pump truck must be fully unfolded to ensure the stability of the operation, and the legs of the spider arm can independently adjust the unfolding length or angle of each leg according to the actual space conditions of the site. .
The operation coverage of the spider arm frame fully matches the high requirements of the narrow space for precise fabric. Its multi-section folding boom structure, combined with the hydraulically driven turning mechanism, can realize 360° full rotation operation, which can easily cover the operation areas that cannot be reached by traditional equipment, such as the reinforced dense area of the bridge box beam, the edge part of the tunnel lining, the narrow operation surface of the bottom of the foundation pit, etc.
The spider leg structure of the spider arm frame eliminates the two core safety risks of narrow space operation from the design level: equipment overturning and pipeline rupture. In the leg support link, the four legs of the equipment can independently adjust the extension length and support height according to the actual slope of the ground on the site, which ensures the horizontal stability of the equipment during operation. In terms of operation stability, the lightweight high-strength boom design of the equipment greatly reduces the vibration amplitude during operation.
The coordinated design of the pumping system of the spider arm frame and the posture of the arm frame solves the problem of pouring quality control in a narrow space from the technical level. On the one hand, the layout of its conveying pipeline is designed synchronously with the arm structure, which fully fits the folding and stretching form of the boom. There will be no significant bending during the operation process, which reduces the resistance of concrete during the transportation process, can ensure the continuous and stable flow of concrete in the pipeline, and reduce the concrete The probability of separation and blockage of pipelines.
From the perspective of comprehensive construction cost, the application cost of the spider arm frame is much lower than that of the traditional pouring scheme; first, the entry and in-place cost of the equipment is greatly reduced; and the compact design of the spider arm frame allows the equipment to enter the site without additional on-site transformation, which greatly saves this part of the cost. Second, the transfer efficiency of the equipment has been significantly improved. Compared with traditional equipment, the installation and commissioning time of the spider arm frame has been shortened by 90%. Some models can even complete the full set of work preparation of unfolding legs and debugging the arm frame posture within half an hour. The spider arm frame adopts the wireless remote control operation mode, and only one operator can complete the fabric operation, which reduces the labor cooperation requirements required by the traditional fabric method and further compresses the labor cost.
| Dimension | spider boom pump | Traditional concrete pump truck |
| Size and mobility | The fuselage design is extremely compact, the width is less than 1 meter after closing, and the height can be controlled within 2.8 meters, which can easily pass through the narrow passage; the requirements for the conditions of the entrance road are extremely low. | The whole machine is huge, which requires a wider entrance road and a large operation space; some large pump trucks need nearly 6 meters of transverse space after the legs are fully unfolded. |
| Work coverage capacity | It adopts a multi-section folding arm frame + full-revolving mechanism design, and the fabric radius covers the range of 13-36 meters, which can achieve 360° pouring without dead angles. | Although the length of the boom is long, it requires a large expansion and rotation space; the boom of some traditional pump trucks cannot be fully unfolded in a space with limited heights. |
| Setup and transition efficiency | The equipment adopts an integrated folding design, and the preparation time for unfolding legs and adjusting the posture of the arm is extremely short; some models can even complete a full set of preparation work within half an hour. | It takes a long time to unfold and adjust the legs and arms of the equipment, and it usually takes 2-3 hours to complete the job preparation. |
| Security and compliance | It adopts a spider-type hydraulic leg design, and the four legs can be adjusted independently to ensure the horizontal stability of the equipment during operation and is equipped with multiple safety protection devices. | The large unfolding area of the legs has high requirements for the ground bearing capacity of the site, and it is prone to the safety hazards of uneven settlement, and the safety risk is high. |
| Security and compliance | It adopts a spider-type hydraulic leg design, and the four legs can be adjusted independently to ensure the horizontal stability of the equipment during operation and is equipped with multiple safety protection devices. | The large unfolding area of the legs has high requirements for the ground bearing capacity of the site, and it is prone to the safety hazards of uneven settlement, and the safety risk is high. |
Before the start of construction, the site plan should be drawn, the parking space of the pump truck and the arrangement points of the legs should be determined, and sufficient pipe turning radius should be left. The machine operation area is strictly separated from the traffic area, and the scene is set up with warning areas and guardrails, equipped with prominent warning signs. All construction participants must participate in the safety handover and clarify the risk points and emergency processes of the pumping operation.
Whether it is a pump truck or a spider lift, a level meter or laser level meter should be used for ground detection after unfolding the legs to ensure that the four feet of the equipment are horizontal. The independent legs of the spider machine allow precise leveling at different heights, but the operator still needs to confirm the final stability. If necessary, place a support pad or steel plate under the legs to prevent the legs from falling into the soft ground.
The connection of the pumping pipe must be firm, and a buffer pressure reducer must be set at the corner to reduce the risk of pipe blockage. When placing a long pipe in a narrow area, you should pay attention to the height of the pipe (to avoid interference with personnel and other equipment) and set up a back pressure valve. During the pumping operation, a special person should be equipped to monitor the condition of the pipeline, and quickly start and stop the equipment when the pipeline is cleaned in time or blocked.
Due to the small space, the coordination between cranes, concrete workers and mecotors is crucial. It should be equipped with walkie-talkies or two-way wireless headphones to ensure that the on-site operators always keep in touch and transmit adjustment instructions in time. The ground commander needs to hold the universal valve switch and accurately operate the injection direction and speed according to the pouring requirements. All operators involved in pumping must be professionally trained and familiar with equipment operating procedures, especially the emergency braking and fault shutdown process.
In response to possible emergency situations such as pipe bursting, concrete back spraying, mechanical failure, etc., emergency plans must be formulated and drilled on the spot. If abnormal expansion of the pipeline or sudden increase in sound, the pumping should be cut off immediately and all personnel should be evacuated in place; if the power is interrupted or the equipment fails, the backup power supply or the backup pump should be switched in time. Ensure that first aid equipment and firefighting equipment are complete, and specify the emergency evacuation route at the same time.
Owning a spider boom lift means that construction enterprises can undertake projects that cannot be reached by traditional equipment, such as historical building restoration, indoor atrium pouring, underground space construction and other high-end or special projects. In scenarios where traditional equipment cannot be safely deployed, such as narrow doorways, slopes, indoor high altitudes, etc., the spider pump truck provides a stable operation platform with anti-fall protection. Operators can work safely on a fenced platform, avoiding the high risk of falling caused by scaffolding or ladder operation.
Although the unit price of the spider boom pump is higher than that of ordinary equipment, from the whole cycle of the project, its comprehensive cost advantage is obvious. Specifically reflected in: reducing the cost of multiple transshipment of equipment; shortening the construction cycle caused by the inability of equipment to enter; avoiding additional expenses on ground protection (such as laying steel plates, repairing damaged ground, etc.); avoiding construction delays and economic compensation caused by noise complaints in sensitive environments; reducing The dependence of tower cranes has released key vertical transportation resources.
Q: What is the difference between spider boom lifts and traditional arm lifts?
Answer: The spider lift adopts a crawler chassis and is equipped with independent adjustable legs. After folding, the fuselage is extremely compact. It can enter the field through the standard door frame and can achieve self-leveling on slopes or unflat ground. Traditional arm lifts rely on tire chassis, which requires a large flat space for take-off and landing, and cannot be transferred in narrow passages.
Q: Can the spider boom lift be used indoors?
Answer: Yes. Most spider elevators are driven by electric or hybrid power, do not emit exhaust gas, and the track pressure is small, which does not damage the ground. This makes them very suitable for indoor space work, such as shopping malls, hotels, lobbies and other places. Many actual cases show that spider elevators can operate in a normal business environment without affecting the surrounding environment or leaving car marks.
Q: What preparations should be made for the construction site before use?
Answer: Generally speaking, spider elevators have lower ground requirements than wheeled equipment, and can operate on a certain inclination and slightly uneveved ground. However, for safety’s sake, the ground load capacity and whether there are flexible areas should be checked. If there is a large drop or mud, local hardening or padding can be laid. In addition, obstacles (such as stones and debris) on the site should be removed to leave enough space for the legs to unfold.
Q: Is the investment cost of spider elevator high?
Answer: The single price of spider elevators is usually higher than that of similar traditional lifting equipment. However, because it can significantly improve the speed of operation and reduce auxiliary costs in a limited environment, it can often achieve a return on investment in the case of multi-project demand. If the project often involves complex space construction, the spider lift can replace many traditional equipment, with good comprehensive benefits.
Q: How to reduce the risk of pipe blockage when pumping in a narrow space?
Answer: For the layout of complex pipelines, the following measures should be taken: choose a wear-resistant pipe with an appropriate diameter and set up a hose joint to absorb shock; install buffer joints or pressure sensors at each large angle; flush the pipeline before the pump stops working to keep the pipeline unobstructed; at the same time, control the concrete pumping speed and pumping pressure, do not Sudden pressurized.
The technical characteristics of the spider boom fully match the concrete pouring operation needs of narrow spaces in modern construction scenarios. With the continuous iteration of the technology of such equipment, its technical advantages under narrow space conditions will be further amplified, and the application scenario will be wider. For procurement decision-makers, the technology of such equipment will be upgraded. The level direction further improves its cost-effectiveness ratio under narrow space working conditions, which is the key equipment selection direction to improve the quality, efficiency and safety level of construction under complex working conditions in the future.
