客运专线桩板结构设计方法的探讨

Discussion on the Design Method of Pile-slab Structure for Passenger Dedicated Railway

研究目的:本文通过对比新型地基加固措施桩板结构在设计中可采用的容许应力法和极限状态法,分析两种设计方法的特点、优势及目前发展现状,并根据实例进行计算和定量分析,以得到一些有用的结论,供设计者参考。研究结论:容许应力法不分构件种类和使用情况,对不同的荷载形式均根据容许强度取统一的安全系数K,使得结构设计偏于安全,较为保守;概率极限状态法以概率统计为根据,具有客观性、合理性,优于带有主观性和经验性的容许应力法。但由于铁路列车荷载的特殊性,其可靠度理论还不够成熟。就目前而言,桩板结构设计时宜采用容许应力法。概率极限状态法可望在不久的将来取代容许应力法。

Research purposes： By comparison of allowable stress method and limit state method adopted in the design of pile - slab structure for new foundation improvement, the analysis has been made on the feature, merit and current development condition of two design methods and the calculation and quantitative analysis has been made according to engineering cases to attain some useful conclusions for designers for reference. Research conclusions：If the allowable stress method is used, it is not necessary to differentiate the kinds and condition of service of the members. According to allowable strength, the different load types have the same safety coefficient K to make the structure design safer and more conservative. Probability limit state method based on probability statistics has objectivity and reasonableness, superior to allowable stress method with subjectivity and experience. However for the particularity of railway train load, the reliability of probability limit state method is not mature. Thereby at present the allowable stress method shall be adopted in the design of pile - slab structure. It is hoped that in the near future probabilitv limit state method will take the Mace of allowable stress method.