| Compared with the foreign advanced technology, China has a late study and application on the system of steel stent of construction technology. The steel stent is divided by use into formwork-support and scaffold. Our country has published standard principles successively, which include "The Safety Criteria of Steel Tubular Scaffold with Couplers in Construction Technology" of2001and "The Safety Regulations of Socket Type Dish Buckle Type Steel Pipe Support in Construction Technology" of2010. In these specifications, it is not safe that the calculation of integral carrying capacity is simplified by carrying capacity of single upright stick. Then there is no relevant regulations pointing out the influence of dynamic load of frame body. Therefore, the current method of theoretical calculation is not perfect. This research makes an experimental and numerical simulation study of the new ring type steel-tube scaffold, which plays a positive role in the popularization and application of these frame bodies.(1) This paper firstly determines the calculation model and analysis method of new ring type steel-tube scaffold through analyzing the calculation theory and numerical model of steel tubular scaffold with couplers.(2) This paper introduces in detail the characteristics of nodes of the ring type steel-tube scaffold, stability of the system and the basic theory of Eigen value bucking load and nonlinear bucking load in numerical model.(3) In the experiment using the tower body of three layers as the carrying capacity of frame body, a600KN hydraulic jack loading device is used to load the ring scaffold tower, DH3817dynamic strain tester test strain to obtain the data of testing carrying capacity after conversation.(4) Based on the test data, the numerical model of the pylon frame body is established. And conduct an analysis of Eigen value bucking load to determine the stiffness K of frame body connection plate. After that, put K in the scaffold program to get the frame body carrying capacity. In order to prove the accuracy of the test value, various calculation methods based on specified theories should be conducted.(5) The research has been done including study of the new ring type scaffold under the condition of the different framework sizes. Considering the variation possibilities to the frame body bearing capacity, the cross range, longitudinal distance and step distance of the upright rod, including the rod sweeping the floor, the installation of the support to the wall, the stiffness of coupling flange, the pipe wall thickness, as well as the effect of load conditions are all involved in the observation.(6) The design calculation of the scaffold frame body has big defects, because the design is based on the statics knowledge per to the scaffold system crash case analysis, which is not matched with the common function from the static and dynamic load in the process of working. Use the framework size of the test model and study the dynamic characteristics of the frame body.(7) The scaffold system is firstly introduced and some current issues rooted in the aspects of theoretical model, horizontal loads, and structural measures are discussed. And then put forward the engineering reliability theory which could be used in evaluating the reliability for the frame body design calculation.At last, according to the research results, the main conclusions and the further improvement of this paper would be reached and perfected. And the significant theoretical guidance would be promoted in the application of the new ring type steel-tube scaffold. |
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