Stress Performance Monitoring And Analysis On The New High-strength Cuplok High Formwork Support System

With the construction of more and more large buildings, such as city overpassand large venues, high formwork support has been widely used in many engineeringand achieved rapid development. New cuplok high formwork support of “Hercules”is the latest new invention. As the stress of support in the actual construction is notclear, and there is no professional standard to guide the design and the construction ofthe new type of formwork support, in order to promote its development and avoid theaccidents, it has theoretical and practical significance for further study on mechanicalproperties of this new high formwork support.Taking Henan province Zhengzhou Sanhuan rapid North Zhongzhou AvenueInterchange Project as background, with field test, I monitored the internal force ofsome bars in box girder formwork support such as standing tube, flat tube cross,diagonal bracing and the top tilting bar, and calculated the internal force according tothe current code. Finally, there are some overall force law that are summarized, anddrawing the following main conclusions:（1）Standing tube in the same axis all showed that the upper axial force is largerthan the lower, which is because the constraint of diagonal bracing share part of theinternal force that should have been passed down, so that the upright rod axial forcedata is larger than the lower. The result is different from calculation of commontemplate support in theory. Therefore, when we design and construct the support, wecan improve the upper part of the vertical bearing capacity by reducing the step of theupper rod to ensure safety.(2) In the process of pouring concrete, all the top rails of support are pressed andthe bottom rails are pulled. General support calculation theory can not ensure the stateof the flat tube cross, so when we design and construct the support, in addition to payattention to the pressure of flat tube cross, but also focus on the bottom flat tube crosswhich is pulled, especially when the load-bearing of the upper support is large, wecan set some tensile structure to the tension bar to improve the capacity of the tubes. (3) In the process of pouring concrete, the pressure of the upper part of diagonalbracing is larger than the lower, and the outside part is larger than the inside. So theupper part of the outside of the diagonal bracing should be of particular concern in theerection of the formwork support. According to some measures such as adding thecouplers, the restraining stiffness of the node of the diagonal bracing can bestrengthened, which can improve the bearing capacity of the diagonal bracing.(4) In the process of pouring concrete, the pressure of the outside bracingsupport tube under the flange is significantly greater than the inside, which tell us thatit’s necessary to control the length of the support tube on the design and erection. Inorder to improve the bearing capacity and prevent it from the loss of stability, it canconstitutes a whole along the longitudinal by the steel tubular scaffold.