Anchors: an inflatable balloon connected to the support structure is one of the core technology products. First, the root angle, the main anchor bolts, wedge angle section fixed to the bed, pouring concrete in place after adjustment. Casting jig and main anchor bolts, support the root angle, the balloon portion supported on the wedge angle, flip to the upstream side of the top panel, relying on casting jigs are pressed and fixed and hinged cover plate and door fixed.