Jacking construction method for prefabricated frame with inversely arranged oil top on variable ramp

Abstract

The invention discloses a jacking construction method for a prefabricated frame with an inversely arranged oil top on a variable ramp. The method comprises the following steps: arranging a weak transition section at a gradient change point, namely breaking a concrete slide way to form a weak section of a soil foundation; inversely arranging the oil top at one end of the prefabricated frame, arranging a rear seat of the oil top in a mode of backing on the prefabricated frame, connecting a piston column of the oil top with a force transfer member bar on the back, applying jacking force to the back through the oil top, and enabling the rear seat of the oil top to push the prefabricated frame to move forward for jacking; and jacking the prefabricated frame, dismounting the force transfer member bar, performing following up pouring on step type concrete rear seats, mounting the force transfer member bar, jacking the prefabricated frame, dismounting the force transfer member bar, performing following up pouring on step type concrete rear seats, mounting the force transfer member bar, continuing to jack, and executing the processes circularly until the prefabricated frame is jacked in place according to the design. The jacking construction method for the prefabricated frame with the inversely arranged oil top on the variable ramp, disclosed by the invention, can be used for ensuring continuous and stable jacking construction of the prefabricated frame on the variable ramp.

Description

technical field [0001] The invention relates to a prefabricated frame jacking construction method, in particular to a prefabricated frame jacking construction method with an oil roof reversed on a variable slope. Background technique [0002] For the high culvert project passing under the railway, the construction plan adopts prefabrication in the working pit outside the railway subgrade, and then the overhead railway is jacked into place according to the design. [0003] After the off-line prefabrication of the main body of the prefabricated frame was completed, it was found that the actual elevation of the upstream drainage culvert did not match the design. In order to solve the problem of culvert drainage, it is necessary to lower the design elevation of the culvert in the railway-related section. After calculation, the elevation drops by 65cm. Since the prefabricated frame has been prefabricated according to the original design elevation, the jacking slideway of the pre...

AI Technical Summary

Problems solved by technology

[0007] 2. Jacking start: see image 3 , ①The front end of the prefabricated frame is in a suspended state. As the prefabricated frame moves forward, the contact surface between the prefabricated frame and the slideway becomes smaller and smaller, and the slideway bears an increasing load per unit area from the self-weight of the prefabricated frame. Concentration, it is easy to cause damage to the slideway structure, and the jacking slideway needs to be reinforced; ②The front section of the prefabricated frame is in a suspended state. Under the action of gravity of the suspended section, it is equivalent to applying a variable torque to the prefabricated frame. "Up-slope point" is the clockwise twisting trend of the fulcrum, so that tensile stress appears on the top and bottom surfaces of the prefabricated frame, which may lead to the destruction of the prefabricated frame structure

[0011] 6. See Figure 7 , the prefabricated frame passes through the downward slope point: ①One end of the prefabricated frame acts on the glideslope, and the other end acts on the slope, forming a concentrated load on the glideslope and the slope respectively, which is very easy to damage the slide and also easy to improve the prefabricated frame. Cause damage; ②The downward slope point is suspended in the air, under the action of gravity, the bottom of the bottom plate of the frame structure and the bottom surface of the top plate are likely to form tensile stress and cause damage to the frame structure

When the jacking slideway is a variable slope slideway, such as Figure 10 shows that when the prefabricated frame 4 passes through the upslope point (such as image 3 and Figure 4 ), the prefabricated frame 4 rotates, the rear end tilts, and the direction of the force transmission rod 3 is not parallel to the axis of the prefabricated frame bridge culvert, so that the force transmission rod cannot transmit the oil jacking force to the end of the prefabricated frame bridge culvert well, and may even It also led to the loss of stability of the dowel members, making it impossible to continue the prefabricated frame jacking construction

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