When the two lining of the tunnel is used as the lining concrete of the two, how to lay the trolley? Please kindly explain steps.
The next two large positioning along the side mode, re positioning of two small side mode along the point, then turn to check the center point and elevation, if not the positioning deviation is complete, then re adjust the positioning deviation! If you have time to measure the location of the site can be set up, then you do not nail this method, the five points directly to the elevation and mileage can be controlled for a long time
The first measurement group with total station will be five points (template center, 2 large side mode along the point, 2 small side mode along the projection point) in lofting invert, with nails into the inverted arch concrete as a symbol, and note the nail surface elevation. The trolley positioning, the first to the two lining trolley running mileage, and positioning, positioning process will have been completed two off the top two tight lining lining, free end positioning first center point positioning control of elevation and with a plumb line (top surface elevation is equal to the length of the plumb line + if the mileage of two the center point of elevation can be lining)
If the template comparison rules, the design center line directly, that is, the center of the car can be, and then measured elevation and the design elevation of the introduction of the real distance from the real point of the vehicle
