CPC E21D 11/183 (2013.01) [E21D 11/381 (2013.01)] | 5 Claims |
4. A construction method of an inflatable folding tunnel reinforcement structure, comprising the following steps:
S1: preparation before construction: determining, based on a location and severity of a tunnel defect, a size and a quantity of each of a steel plate, a vertical support plate, an arc-shaped support plate, an upper support rod, a lower support rod, and a threaded steel rod, an output power of an induction motor, and a specification of an airbag; and transporting materials and devices to a construction site;
S2: device fixation: erecting the vertical support plate and the arc-shaped support plate on site; assembling a scissor folding mechanism, and fixedly connecting the scissor folding mechanism to the vertical support plate and the arc-shaped support plate; fixedly connecting the steel plate to the scissor folding mechanism; adhering the airbag to the steel plate; and fixedly connecting a water blocking net to an outer surface of the airbag;
S3: establishing a three-dimensional (3D) coordinate system O-XYZ based on an intersection point O between a geometric center of the inflatable folding tunnel reinforcement structure and a ground as an origin, wherein the 3D coordinate system O-XYZ comprises an X-axis direction parallel to a transverse arrangement direction of the vertical support plate, a Y-axis direction parallel to a longitudinal arrangement direction of the vertical support plate, and a Z-axis direction parallel to a central axis of the arc-shaped support plate; an external pressure on each surface of the inflatable folding tunnel reinforcement structure is F; the vertical support plate has a height of H1, and the arc-shaped support plate has a radius of R; the vertical support plate and the arc-shaped support plate each have a thickness of a and a length of b; the steel plate has a density of ρ; the upper support rod of the scissor folding mechanism forms an angle of θ with the threaded steel rod; in the scissor folding mechanism located directly above the arc-shaped support plate, coordinates of two bottom through-holes A and F of the lower support rod are (0,0,H1+R) and (0,0,H1+R), respectively, and coordinates of two top through-holes C and D of the upper support rod are (0,0,H1+R+2Lsinθ) and (0,0,H1+R+2Lsinθ), respectively; coordinates of left and right hinge points B and E of the threaded steel rod are (0,Lcosθ,H1+R+Lsinθ) and (0,−Lcosθ,H1+R+Lsinθ), respectively; and the left hinge point B of the threaded steel rod is moved at a speed of v0 under an action of the induction motor;
S4: calculating a mass of the steel plate as follows:
m=ρV=18bρ(2aR+a2);
calculating forces exerted on the upper support rod and the lower support rod of the scissor folding mechanism as follows:
![]() where g is the gravitational constant;
calculating, when θ=90°, a minimum force exerted on the upper support rod and the lower support rod as follows:
![]() calculating the output power PB of the induction motor to the left and right hinge points B and E of the threaded steel rod as follows:
![]() S5: carrying out a construction at the construction site, if, based on the external pressure F exerted on the scissor folding mechanism and a gravity mg of the inflatable folding tunnel reinforcement structure, the induction motor is configured to provide a sufficient output power for the scissor folding mechanism;
S6: on-site construction: turning on the induction motor to start working; driving, by the induction motor, the threaded steel rod to rotate clockwise; allowing the upper support rod of the scissor folding mechanism to form an angle of θ with the X-axis direction; unfolding the upper support rod and the lower support rod in opposite directions through the threaded steel rod at a rotational speed of v0; turning off, when an outer wall of the steel plate reaches a preset position, the induction motor to stop working; and inflating the airbag through an inflation port to complete a reinforcement;
S7: structural inspection: checking working states of a locking pin and a rolling connection pin in the scissor folding mechanism, as well as drainage performance of drainage channels in the water blocking net; and
S8: site cleaning: cleaning up the construction site after the tunnel defect such as peeling and leakage in the segment is corrected and the segment returns to a normal state; and checking the inflation port, the airbag, the water blocking net, the steel plate, the scissor folding mechanism, the vertical support plate, the arc-shaped support plate, the drainage channels, the upper support rod, the lower support rod, the locking pin, the threaded steel rod, the rolling connection pin, and the induction motor, so as to ensure a normal operation of a tunnel.
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