Study On The Calculation Method Of Internal Force Of “Well” Shaped Beam Grid Bottom Board Sluice

Baolangsumu sluice,built on the silty sand foundation in the south of Xinjiang, is a kind of sluice with lightweight structure,its pier is arranged on the two sides of the upper chamber,which is separated from the lock floor.The chamber consists of the “well”shaped beam bottom board and bridge column frame.The sluice of the special structure is designed cleverly, relative to the traditional flat plate sluice, it saves the amount of reinforced concrete chamber. But because the chamber structure of the “well” shaped beam grid bottom board is more complex,it has not yet formed a complete set of mature and complete internal force calculation method,to a certain extent, it affects the application and popularization of this special structure type sluice in the silt foundation of Xinjiang.In view of the structural design characteristics of this sluice,respectively use section method, elastic foundation beam method and finite element method to calculate and analyze the internal force of this special chamber structure. The main conclusions are as follows:(1)Through the analysis and calculation of the internal force of the “well” shaped beam grid bottom board of sluice structure,it is found,using section method, elastic foundation beam method and finite element method is able to obtain the internal force of the chamber of the main structural members, and the law of distribution of internal force of each component of three methods calculation income is similar.(2)Under the condition of dry condition and water retaining condition,use the three methods of section method and elastic foundation beam method and finite element method to get the calculation results of the chamber at the bottom of the “well” shaped beam grid bottom board in the beam lattice system showing that:maximum bending moment and shear force at the intersections of the stringer II, stringer III and the cross beam, the beam I moment reaches maximum value at girder span, and shear force reaches the maximum value at cross beam.(3)Analyzing the calculation results of the internal force of each beam in the “well” shaped beam system by using the three methods, it is found, the internal force value with elastic foundation beam method calculation is close to the calculation results with the finite element method, while income values of calculation internal force with section method are bigger, but from the beam section design and reinforcement analysis, calculation result with section method is on the safe side.(4)The key of correctly calculating the internal force of each beam of the “well” shaped beam grid system by using the section method is reasonable to simplify the superstructure of bridge pier and the traffic bridge beam chamber,to establish a mechanical analysis model suitable for the section method;when using elastic foundation beam method to calculate this special structure, in addition to the simplified structure in the upper part of the lock chamber outside, we should also pay attention to select reasonable subgrade reaction coefficient K.(5)Through using the finite element method to imitate and calculate the chamber under different foundation elastic,the results show that,when the elastic modulus of foundation changes within a certain range, the change of internal force of the lock structure is not obvious.It shows, at different elastic modulus,the adaptability of the sluice structure of the “well” character shaped beam is better.