Comparative Study On The Specifications Of Highway Steel Bridges In China,France And The United States

With the rapid development of engineering globalization,facing the same steel bridge construction requirements,the design results of highway steel bridges in different countries will be different.In Africa(such as the Republic of Congo),many road bridge designs and constructions are undertaken by Chinese,French or American company.Therefore,this article takes China,France,and the United States as a research background for the design of highway steel bridges.Steel Structure Bridge Design Standard "JTG D64-2015(referred to as China Standard)," European Structure Standard "EN1993 steel bridge design standard(France adopted this standard,referred to as French standard)and the United States" AASHTO LRFD Bridge Design Specifications "(referred to American standard)to conduct a comparative study.About the comparison,the important conclusions are as follows:1)First,a comparative study of the steels in the three standards is carried out.The results of the comparative study show that the maximum yield strength of Chinese standard steel is smaller than the maximum yield strength of American standard steel.The maximum yield strength of the American standard steel is greater than the maximum yield strength of the French standard steel,indicating that Chinese steel still needs to be strengthened in the production and manufacturing technology of high-strength steel.2)Secondly,a comparative study on the steel structure connections in the three standards.The results of the study indicate that the pretension of the high-strength bolts is about 10% lower than the European standard and about 15% lower than the American standard.The American standard has a design strength value of bolts that is1.56 times greater than the Chinese standard;in butt welds,the Chinese standard and the French standard also consider the form and size of the cross section,but the scope of the Chinese standard is larger than the French standard;The calculation method and results are more detailed than the American standard.The Chinese and French standards are not safe under the same circumstances,but they are safe according to the American standard.3)Then,the stability design of the steel bridge is compared.The research results show that the design of the local stability of the web in the Chinese standard is analyzed from the maximum stress and the minimum stress,while the French standard does not take into account,but the French standard design of the web Thevalue specifies the stress distribution.It can be seen from the calculation example that the calculated value of the ultimate bearing capacity of the American standard is greater than the calculated values of the ultimate bearing capacity of the Chinese and French standards.There is a very small difference in the resistance design value stipulated by the Chinese standard and the French standard,not exceeding 3%.In calculating the overall stability of the box girder,the Chinese standard is more conservative than the American standard.4)Finally,taking the design of a continuous steel box girder bridge as an engineering example,the main load effects are compared and analyzed.The research results show that under constant load,the calculated bending moment value obtained by the Chinese standard is 1.6% to 1.9% larger than the calculated bending moment value of the French standard.The calculation results of various national standards are quite different: the shear load and bending moment effect of the Chinese standard car load is 8% smaller than that of the French standard;but the load load shear and bending moment effect of the Chinese standard car is 22% larger than that of the American standard;.In terms of temperature effects,the temperature effect of the American standard is the smallest,and the temperature effect of the Chinese standard is smaller than that of the French standard.