Improvement of bolt-hole support technology for concrete equipment foundation

The construction of the concrete foundation of the west building is reserved for bolt hole die technology. The construction characteristics, process flow, operation principle and key points, material selection, construction tools, construction and quality requirements of Cao Guoxiong and Fan Xing'an are elaborated. The engineering example proves that the method not only has simple construction, but also can guarantee the construction quality well, and also receives good economic and social benefits.

In recent years, the construction of industrial plant buildings has been equipped with some concrete equipment foundations, and the construction of bolt holes in the concrete equipment foundation often occupies a considerable proportion, including the construction of medium and small bolts, as well as some large bolts. Hole handling. In these projects, the construction of large reserved bolt holes is a difficult point in construction. On the one hand, due to the large thickness of the concrete foundation, the reserved bolt hole template often has shortcomings such as insufficient fixed rigidity. In the process of watering, pouring and vibrating concrete, the template of the reserved bolt hole is displaced due to the impact or vibration. Or local deformation; on the other hand, due to the large amount of concrete pouring, when the upper concrete is poured, the lower concrete has been finally set, so that the concrete is bonded to the formwork as a whole, and in the conventional process, the bolt holes are reserved. Using a wooden mold as the core, the wood absorbs water and expands. It is quite difficult or impossible to remove the template, which becomes a difficult point in construction.

In view of the above construction difficulties, we have adopted the method of externally tying the steel cage and then using the polystyrene core to wrap the fiber box, which better solves the above problems. In the practice of Datong 300,000 t coal-water slurry No. 1 ball mill unit, No. 2 ball mill unit and Linyi Sanji coal washing plant ball mill unit foundation concrete project, our steel cage fiberboard box construction method is not only simple and simple, but also better. The construction quality has been guaranteed, and the use of the above projects has received good economic and social benefits.

1Features 11 This method is not only suitable for foundation construction of concrete equipment, but also applicable to the construction of reserved holes for all cast-in-place concrete, especially for deep reserved holes, which can show the advantages of this method.

12 The method is simple and effective, the materials used are inexpensive, and the construction method is not limited by the on-site operating environment.

2 Operation principle The principle adopted by the method is that the position of the reserved hole is basically fixed by the steel cage, and the reserved hole formed by the solid core box of the polystyrene board formed by the fiber board. After pouring the concrete to the final setting, the polystyrene board in the template can be removed by using a steel bar on the spot of 14 mm or more. After the cleaning is completed, fill the template box with water. After the water is soaked, the fiberboard is removed.

3 Process flow and operation points I will reinforce the steel cage in the 丽: dish s into the steel cage word business building concrete ugly concrete after the final condensation, the template box inside the polystyrene board clear letter 'dimensional plate inside the water injection H fiber box After the foam is soft, the template is removed. I. Operation points T) The steel cage preparation material should not be less than the secondary (1) (1). The inner diameter of the steel cage is 10mm larger than the size of the reserved hole on each side. The four reinforcing bars and the welded beard are placed at a distance of 40cm ~ 60cm. The fixing of the steel cage in the concrete foundation is a key link, and the bolt is released in the basic formwork. The position of the hole, the reinforcing cage is fixed with the structural ribs in the foundation, and the rigidity and stability of the steel cage are determined according to the depth of the reserved hole. At the appropriate part, the beard rib on the standing rib is also fixed with the structural rib, and the reinforcing cage and model above The tie rod is fixed. 2) The fiberboard box is connected with four 25mmX25mm small square wood. 3) The fiberboard mold box is filled with polystyrene board material. 4) When pouring concrete, a wood molder should guide the concrete pouring on the site, and synchronously pouring from the periphery of the mold box. Never use the car and the hopper to directly pour the concrete from one side to displace the steel cage and the mold box. Reinforcement cage and fiberboard box structure see and fiberboard structure 圉 2 2 Reinforced cage cage 咄 4 4 material Reinforcement cage selection of ordinary A3 steel 8mm steel. The polystyrene board is required to be cut into strips that are consistent with the width of the template. Preferably, the fiberboard box is full of each template surface. If the length of the fiberboard is insufficient and needs to be spliced, the joint should be placed on the upper part of the template. The small square wood of the nail box board is preferably made of long red and white pine wood.

5 Construction tools In this method, the steel cage is made by welding with a general electric welder. The ordinary woodworking tools (small chainsaw, seven-point nails, small hammer) for the interception of fiberboard and small square wood are required. Cooperate with the woodworker, the size and requirements of the steel cage shall be made by the woodworker to the bottom of the steel bar, and the steel bar shall be kept away from the woodwork material during welding to prevent fire.

7 Quality requirements The hole size is reserved according to the drawings. The inner edge of the steel cage should be larger than the reserved hole by 10mm. The outer dimension of the fiberboard box is the required reserved hole size. The fiberboard box can be supported by a small square 25mm column with a square beam. The fiberboard is connected with a small square wood with a seven-point nail.

8 Benefit Analysis From the engineering practice analysis, the use of this method can save 85% of wood compared with the traditional wood mold process, and the template production efficiency can be increased by 4 times, especially the solution of the reserved bolt hole template Fan Xing'an (1953~), male, 1973 Graduated from the Shanxi Provincial Construction Engineering School, civil engineering construction, engineer, Shanxi Construction Engineering Group Corporation, Shanxi Taiyuan 030002, Zhaoshandu diversion tunnel construction technology Yang Qi five division projects have been introduced in detail. At the same time, the engineering characteristics were also analyzed, and the corresponding construction techniques were adopted according to their characteristics. After quality inspection, the pressure reached 80% of the design pressure and the water permeability was qualified.

The Zhaoshandu water diversion project is a large (2) type diversion project mainly based on water supply, and is an integral part of the Shanxi Water Conservancy Project. The nine-standard canal built by our project department belongs to Nangan Canal, with a total length of 7.589km. The range is: Nangan 9+013. 5~16+602. There are two diversion tunnels. The Xujing tunnel (1/2) is 2 059.5m long and the section form is 4. 1mX3.88m. The Shitangling tunnel has a length of 3 837.5 m and a section shape of 2.4 mX 3.04 m.

2 Working contents and characteristics of the diversion tunnel The design of the diversion tunnel section of the 21-hole excavation water conservancy project is weaker than that of the railway tunnel. The safety protection of the tunnel tunnel opening has formed a set of universal and complete technology. In order to ensure construction safety and building safety, it is best to construct a tunnel outside the cave (Myeongdong or culvert) before the tunnel is drilled to stabilize the cave face and improve the safety factor of the tunnel construction. The tunnel construction specification of the water conservancy project stipulates that the excavation of the excavation is strictly prohibited, and the over-excavation is controlled. The radial over-excavation value is not more than 10cm, and all loose rock blocks should be completely removed. The over-excavation backfill must be backfilled with the same number of concrete and not metered. . The advantages and disadvantages of blasting technology directly affect the economic benefits of the unit. The section of the Zhaoshandu diversion tunnel is small (divided into two types of excavation sections. The A-type 14.74m2 of the Xuyu tunnel is small, and the blasting surface of the B blasting is small, and the effect of blasting is obvious. For this feature, we organize technical cadres to cooperate with the blasting class. Grab the smooth blasting. Determine the different blasting methods according to the different firmness and integrity of the surrounding rock on the site; smooth blasting, reserve smooth blasting, pre-splitting blasting, adjust the blasthole depth, blasthole spacing, Relevant blasting parameters such as charge structure, charge concentration, and gutter form. Take the Shitangling tunnel as an example. If there are similar vertical and horizontal bedding, joint fissures and mezzanine faults, we use the surrounding rock. Small pre-splitting blasting with turbulence, vertical wedge shape of the sulcus, 3 pairs to 4 pairs of sulcus eyes, 35cm~40cm of peripheral eyes, 35cm distance to internal cataract, and concentration of peripheral eye charge 0. Charge, the depth of the blasthole is 2m, and the number of blastholes is 32. For example, the hard whole rock layer is blasted with a reserved smooth layer, the gutter is a cross shape with four eyes, the peripheral eye spacing is 60cm~70cm, and the peripheral eye resistance line is W=70~80. Charge set The degree is 0.2kg/m~0.3kg/m, the depth of the blasthole is 2m~2.3m. In other cases, smooth blasting is used. The distance between the peripheral eyes is 35cm ~ 60cm, the minimum resistance line of the peripheral eye is 60cm~75cm, and the concentration of charge is 0.2kg/m~ 0.3kg/m, the form of the gutter is the same as the reserved light explosion method, and the depth of the blasthole is 2. 3m~2.5m. Through the continuous exploration and experience of the scene, the light explosion effect is continuously improved, the undercut is eliminated, and the over-excavation is controlled. Reduce costs and increase efficiency.

The main function of the 22-cavity lining water conservancy project is to supply water, so the water quality is clean. At the same time, its stress characteristics are different from those of railways and highways. In addition to the normal surrounding rock pressure, it is also subject to internal water supply. The water pressure and the flow scouring force and vibration force also have the balance of water and waterless force balance. Therefore, the cleanliness of the rock face is extremely high to ensure the adhesion between the concrete and the rock face. In view of this feature, during the excavation construction, the water curtain is used for dust reduction in the drilling and blasting, so that the dust dust is controlled in the working surface range and not spread to cause large-area pollution. The excavated rock face should be excavated. The transportation facilities should be transported by electric motor to avoid the oil and pollution of the steam and diesel equipment. The floor and lining should remove all the floating rafts, dust and accumulated water. Rock dust and dust, the oil is completely removed before opening the warehouse. The concrete of the water tunnel has anti-seepage requirements. The concrete coarse aggregate generally requires double-stage and above. The Zhaoshandu water diversion project adopts 0. The problem of difficult to dismantle, greatly shortens the construction period of the reserved hole construction and reduces the construction cost. The process is in Datong. The No. 1 ball mill unit and the No. 2 ball mill in the coal water slurry pulping workshop simplify the construction process. The application of the group and the Linyi three prison ball mill unit has achieved good results. The construction of the application form is low, the construction period is short, and the construction quality is also well guaranteed.

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