The Analysis And Study Of High-rise Pile Cap To Tower Crane Foundation

Nowadays in most of modern constructions, the crane is essential construction machinery. In a large deep excavation project, there is a new form of foundation set for tower crane– the high-rise pile cap. In modern large-scale deep excavation project it has been widely used. The strained condition of this new form of foundation is complex, it is often supported by steel concrete pillars, and the strained condition of steel concrete pillars itself is very complicated, which makes the analysis and research of this new form foundation become more difficult, meanwhile, the design of foundation is reasonable or not ,that is also should be concerned. Through literature search, the research reported in this area is still very little. And more research in this new form foundation focus on the construction, as for the actual stress state is still need much more concern.In response to this new form of the tower crane foundation, this paper proposes a method for the first time: use finite element analysis software SAP2000 for the static stress condition of foundation lattice column, and its status in the live load, using strain gauge for stress testing, and then, incorporate with analysis of these two parts, give the whole high-pile cap stress condition state.Making use of SAP2000 finite element software for analysis and calculating, set up three-dimensional model in line with the actual structure. Using the various parameters from actual materials and components used in the high-rise pile cap, taking the tower crane technical parameters as the load model parameters that applied to the model. And analyze stress condition state of the entire high-rise pile cap foundation when the crane does not work.For dynamic loads, collect data by testing on the actual structure making use of BZ2205C-static strain gauges. When the crane is working, detect the strain on lattice columns with the strain gauge, this strain is response to the dynamic load on lattice columns during the crane's working, this strain response reflects the real stress condition state of lattice columns. Through the analysis of cantilever part, the measuring points are set in the most dangerous position of cantilever part that is lattice column roots, and strain foils are attached to the measuring points. The results of analysis and research show that the proposed technical route is practicable. The study of a high-rise pile cap foundation design is tend to somewhat conservative. And proposed to reduce appropriately weight of concrete of concrete-filled steel tube under meeting the basic design requirements, reduce the whole structural weight, and reduce the cost of whole high-rise pile cap foundation. These studies for new form of the high-rise pile cap foundation provide quantitative guidance to design optimization and cost optimization.