青藏线波纹管涵洞现场试验及理论分析

以位于青藏线DK945 849,海拔高度在4 200 m以上的一座金属波纹管单孔试验涵洞(孔径1.5m)为背景,进行新型波纹管涵洞管壁应力的试验研究。施工过程中不同填土高度下,波纹管不同断面和部位应力的试验结果表明:各测点波峰、波谷的应力随着填土高度的增加迅速增大,波中点应力的变化不大;波纹管涵洞的控制截面是管顶和管底;最大应力出现在路肩下的截面,达170 MPa。该金属波纹管在施工过程中安全系数为1.68,在规范允许范围内。将实测土压力作用在裸管上,进行管壁应力理论分析和有限元计算,其结果略大于应力实测值,误差较小,且偏于安全。验证了实测管壁应力和土压力值的正确性,说明理论分析和有限元分析可用于波纹管涵洞的设计。

Field Test and Theoretical Analysis of Corrugated Pipe Culvert on Qinghai-Tibet Railway

This paper takes an experiment of one corrugated metal pipe culvert(with aperture 1.5 m) on Qinghai-Tibet railway DK945 849 at the attitude of 4 000 m as research background.Test study has been conducted on tube wall stress of new type corrugated metal pipe culvert.The stress at various sections and positions of corrugated metal pipe has been tested with different depth of filling during construction.Test results show that the stress values of each test point in the wave crest and wave trough increase quickly with the increment of filling depth.The change in the stress value of wave midpoint is little.The control sections of corrugated metal pipe culvert are pipe top and pipe bottom.The maximum stress occurs at the section under road shoulder as high as 170 MPa.The safety factor of this corrugated metal pipe is 1.68,which is within the allowable scope of criterion.Theoretical analysis and finite element calculation of pipe wall stress are carried out by applying field measured soil pressure to the pipe.The results are little larger than those obtained by field tests,with few errors and safer.The correctness of pipe wall stress obtained by field tests and soil pressure value has been validated,which indicates that theoretical and finite element analysis can be adopted for the design of corrugated metal pipe culvert.