Single and multi-stitch seam joints comparison of single seam joints joints: a compression force of contraction of 1.0KN / m; 2 joints work within the scope of longitudinal shear force 2.0KN / m.. Multi-seam joints: a contraction compression force 1.0KN / m; 2 done when tensile force 4.0KN / m; 3 scope of work within the joints longitudinal shear force 3.0KN / m multiple type bridge expansion joints.. construction and installation steps: 1, the construction unit must be provided in accordance with the size of the design drawings, the end of the beam (or plate side) and the end of the beam, girder bridge abutment at the end of the telescopic device installed aside aside chutes, and drawings pre- burying anchor bars, beam end anchorage or tendon should have a reliable anchor abutment joint, such as when you need to weld reinforcement shall meet the relevant provisions of the bridge construction norms. 2, factory assembled groups of type bridge expansion joints generally shipped from the factory site. During transport, the transport due to length restrictions, or because of other reasons splice site when required, should guide the production plant under construction. When the telescopic device need to be stored on site, from the ground to the pad should be at least 30cm, and shall not be open storage. 3, before the bridge expansion joint device, you must first check after the completion of the construction of the main beam (or plate) at both ends of the seam gap amount is consistent with the design value, anchor bars or embedded component location is accurate. 4, before hoisting telescopic device should be set aside to fight hair concrete tank, cleaned. The center line and the center line of the bridge stretching device installation coincides maximum deviation of no more than 10mm, and its top surface elevation consistent with the design elevation, and then the anchor bars on both sides of the telescopic device with embedded steel beams best Meanwhile weld. 5, after the completion of the above steps, install the necessary templates, requiring nearly design drawings, reserved slots in the concrete pouring concrete epoxy is greater than C30. Should take the necessary measures to pouring concrete, vibrating compaction and concrete to prevent infiltration MZL telescopic device displacement control box, and do not allow the concrete splash fill in cracks and surface sealing rubber band, if this occurs should be immediately removed , and then make good conservation. May also be greater than or equal C50 high strength concrete filled tamping. 6, before the pavement, multiple type bridge expansion joints should be sealed temporary protective measures to prevent the direct impact and vehicle load to bear. After the completion of the bridge deck pavement condensate gap should not have appeared.