The installation of the Bailey beam must be discharged according to the design location. According to the spacing between the piers, the mid-span 50m box girder support frame length is 48m, which can be adopted according to the seven-span (8+2+11+2.5+11+2+8)m structure; the side span 35m beam support frame length is 29m, The span adopts a (10+2+8.5+2+8)m structure. The Bailey pieces are connected by a support frame, and are assembled by a crane after being assembled on the ground. When the Berea beam is installed, try to place the position of the Beray pole on the I-beam. Channel distribution beam construction A channel distribution beam is arranged on the top surface of the Bailey sheet longitudinal beam. The channel steel specification is [16a, the channel steel buckle is on the Bailey beam. According to the design spacing, the encryption section spacing is not more than 45cm, and the remaining 60cm. The lap joint of the distribution beam must be placed on the longitudinal beam to avoid the vertical pole arrangement of the suspended probe full bracket construction: the longitudinal spacing of the vertical pole is 60cm, and the spacing between the beam end and the middle beam is 40cm. The lateral spacing is 40 to 45 cm under the side web and the middle web, 60 cm in other parts, the longitudinal spacing of the lower vertical rails is 60 cm, the lateral spacing is 90 cm, and the bottom step is 20 cm.
1. The crossbar has a step distance of 120cm except for the top and bottom step distance of 20cm. The height of the bracket is adjusted by the top bracket. The rod is supported on the laid distribution beam by the lower support. The upper part of the rod is supported by the upper support bracket and the transverse shear support is arranged every 4 rows, and the top and bottom of the bracket are provided with horizontal scissors. The angle between the axis of the transverse scissors slanting rod and the horizontal line is generally 45°~60° to ensure the lateral stability of the bracket. All the scissors slanting rods must be set long. When the length of the single steel pipe is not enough, two fasteners are connected. The fasteners must be fastened and fastened to ensure reliable transmission. All vertical and horizontal bars that intersect the slant bar must be reliably connected to the slant bar.
2. The bottom mold of the box girder and the side mold construction bottom mold are directly laid on the square wood with 12mm thick bamboo rubber board, fixed with small iron nails, so that the bottom mold and the bottom of the box girder are exactly the same, and the axis and elevation are adjusted. Install the box girder side mold after meeting the requirements. The side stencils are installed sequentially from one end of the beam, requiring tight seams and flat joints between adjacent stencils. The side mold arc chamfering is cut by a 110mm diameter PVC pipe, installed according to the requirements of the drawings. The rest is made of wood mold, the back rib is 10cm square wood attached to the back of the plywood as the transverse rib, and the square wood support and the steel pipe oblique support are used for reinforcement. Arranged at a distance of 30 cm in the horizontal direction, so that the longitudinal formwork is sewn on a line to ensure the appearance quality of the box girder. The pre-pressing scheme of the bracket pre-pressing bracket is to check the strength and stability of the bracket and the foundation, eliminate the elastic deformation and inelastic deformation of the bracket, and measure the elastic deformation data of the bracket to set the pre-cavity of the cast-in-place beam template, and pre-stress the bracket. The preload load is 110% of the maximum load of the beam construction.
3. Accurate measurement during preloading can measure the elastic deformation value and foundation subsidence value of the bracket under the beam load, and the elastic deformation value, foundation sinking value and other reasons proposed in construction control The factor needs to be set to pre-cavity superposition, calculate the pre-camber degree that should be used during construction, and adjust the bottom mold elevation according to the calculated pre-camber. Measuring point layout? Measuring point layout principle: each of the two ends of the beam, 1/4 beam span, mid-span, 3/4 beam spans are set with 5 measuring points, a total of 65 measuring points.