I. Borrowing Cases
The most difficult part of the pipe belt machine in the transformation project is to find the footing point of the leg of the pipe belt machine after the line is determined. This footing point can be described by stitches.
If it is really impossible to make a foundation on the ground, you can consider using the existing plant roof, the existing belt corridor bracket, pipe corridor bracket, transfer station, etc., but to borrow these structures to support the pipe belt machine, generally need to carry out structural accounting Forced load. Many old buildings have a long history, and the owner generally cannot provide the structure and foundation construction drawings of the building. It will be very expensive to perform the calculation of the strength. In this case where accounting is required, it is possible to not borrow as much as possible.
Borrowing plant pillar
The above picture borrows the two pillars of the existing iron powder yard building, because both sides of the building are roads, and the road side and the ditch are not allowed to be occupied. Two-leg steel column support was made on the column top of the factory building, and structural calculations were performed separately. At the same time, adding steel columns from the roof, the construction was troublesome. You must first clean up the factory column top, and also consider the rainproof measures of the roof.
Borrowing dust suppression net post
The above figure borrows the pillars of the wind and dust suppression net, because one side of the dust suppression net is the road, and the other side is the retaining wall and the road. It is necessary to consider the traffic and be beautiful. Taking into account the cantilever force situation, additional support was subsequently added.
Borrow transfer station beam
The above picture is a transfer station that borrows the existing belt corridor. Because the belt conveyor on the same floor is invalid, it can be used. This load is no problem. The main consideration is the space position to pass through. This belt conveyor has a total length of about 1 km and an average overhead height of about 18 meters. The original design only had a head and tail transfer station with a mouth for the upper and lower equipment. The owner felt it was very inconvenient for maintenance and inspection, so it was close to the quarter of the head. Another advantage of borrowing a transfer station is the addition of an entrance to the upper and lower pipes. Later, according to the convenience of the owner, at a transfer station close to the tube conveyor near the 1/4 total length of the tail of the tube conveyor, the owner built a new inclined ladder to the tube conveyor walkway, which added an upper and lower pipe. Bring machine access.
Borrow transfer station pillar
The above picture shows that the pipe belt conveyor passes between two concrete transfer stations. The original design is to provide foundation support in the gap between the transfer stations. The owner considers reducing the construction cost and recommends that it be better to directly hold the transfer station pillar and support it with a bull's leg.
Borrowing pipe column
The above figure borrows a pipe column, and a mast support is added directly above the existing column. The ground is an access road and no foundation is allowed.
Cases of non-borrowing
Increase long-span trusses
The picture above shows a large span of nearly 50 meters from the trestle bridge. The ground in this area has an oblique wool slope with a height difference of nearly 10 meters, staggered belt corridors and pipelines in the air, and a simple brick-wall flat roof. The original design did not have this large-span truss. The initial plan was to borrow an existing flat roof and build a structural frame on the roof. The structural frame focused on the flat roof wall, and then a column was supported on the structural frame to support the pipe belt machine. The owner of the latter plan denied it, mainly because the flat roof could not withstand this force (the house could not be demolished).
The picture above is a photo of the long-span truss before hoisting.
Without a flat roof support point, you can only use a large-span truss. This large-span truss is also limited by the construction space on the site, which makes it difficult to lift. After designing multiple lifting schemes for multiple evaluations, it finally called 300-ton crane.
Increase the difficulty of column installation
In some places, if you cannot borrow the existing building, and it is not convenient to enlarge the steel structure corridor, you can't avoid the need to increase the truss columns. The figure below shows the two transfer stations. The design of the transfer station structure did not consider the load of the belt conveyor. The design institute did not agree that the truss would fall directly on the transom station beams, and had to add columns inside the transfer station. The pipe belt machine structure is relatively troublesome to lift.
The picture below cannot use the belt conveyor corridor as a support, but can only build columns in the intricate pipes and the only space between the corridors. The column cannot be upright to the top, space and foundation are limited, and it can only be made into a small upper part and a large upper part, and the upper part holds the belt conveyor corridor. The height of the entire column is 21 meters. The biggest problem with this design is lifting and welding. The bottom four-leg column is not disconnected on site. As a whole, how can it be hauled in and installed in place? Be careful to touch the surrounding gas pipes. It is to make split hoisting on site, and then assemble and weld at high altitude. The installation of this column takes the longest time.
总结 Summary two points through the above case studies:
1. When the existing building structure is under stress, it can be borrowed and borrowed as much as possible. This has two main advantages: First, it saves space, especially the renovation project of the plant area; second, it saves the cost of civil infrastructure and equipment investment .
2. When the existing building cannot be borrowed, the new foundation of the pipe belt machine should try to avoid the existing building foundation to ensure that the two foundations do not interfere, so that the force will not be affected.
Other experience summary:
1. For tube conveyors with a long distance of more than 1 km, transfer stations that can be borrowed in the middle, etc., can be used as passages up and down;
2. Near the house building, the center position of the supporting leg of the pipe belt machine must be at least 1.5m away from the edge of the house building wall. It can be as large as possible, because the house's foundation platform and the pipe machine foundation support It is best not to interfere.
3. Close to the belt gallery bracket and the pipe bracket, the distance between the center of the supporting leg of the pipe belt machine and the center of the original bracket should be at least 1m. It can be as large as possible when it is large.
4. If it is unavoidable that the design foundation such as the need to be close to the building is required, special treatment is required during the foundation design.