清洗后的劣化道砟直剪力学特性分析  

Analysis of Mechanical Characteristics of Degradation Railway Ballast by Direct Shear Test

作　　者：井国庆[1] 黄红梅 常锦秀 强伟乐 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《西南交通大学学报》2017年第6期1055-1060,共6页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金资助项目(U1234201)

摘　　要：为探究劣化道砟力学特性及其循环利用机理,分别针对清洗后掺加不同比例新道砟的劣化道砟,结合洛杉矶磨耗试验仪和应变控制式直剪仪,开展了不同比例新旧道砟混合体的直剪试验,探讨了不同垂压(50、100、200 k Pa)下不同比例新旧道砟混合体应力应变特征.研究结果表明:劣化道砟抗剪强度随新道砟含量增多而增大,如100 k Pa垂压下,新道砟含量为50%和100%的样本抗剪强度分别为143.4 k Pa和176.7 k Pa,比劣化道砟抗剪强度分别提高了24.0%和52.9%;劣化道砟剪胀现象随新道砟含量增多而越不明显,如100 k Pa垂压下,新道砟含量为50%和100%的样本最大剪胀量分别为9.842 mm和7.969 mm,比劣化道砟最大剪胀量分别降低了25.8%和39.9%;清洗后劣化道砟力学性能与新道砟差别较小,在一定条件下可与新道砟混合重复使用.In order to study the mechanical characteristics and reuse of a washed recycled ballast, a Los Angeles abrasion tester and strain-controlled direct shear apparatus were used in experiments to investigate the stress-strain characteristics of recycled ballast with different proportions of fresh ballast under different normal stresses （ 5 0,100,and 200 k P a ） . Based on the experimental re su l ts , the mechanical features of the ballast were discussed. The results show that ballast strength increased with the proportion of fresh ballast. The strength of mixtures with 50% and 100% fresh ballast were 143.4 and 176.7 kPa , respectively, under normal stress of 100 kPa; an increase of 24. 0% and 52. 9% , respectively, compared to pure recycled ballast. The shear dilatation of the mixture also increased with the proportion of fresh ballast. For 50% and 100% fresh ballast samples, the values are 9 . 842 mm and 7.969 mm, respectively, under normal stress of 100 kPa; a decrease of 25. 8% and 39. 9% , respectively, compared to pure recycled ballast. There was a small difference in mechanical characteristics between washed recycled ballast and fresh ballast, and the washed recycled ballast canbe reused with fresh ballast under certain conditions.

关 键 词：劣化道砟 新旧道砟混合体 直剪试验 力学特性 

分 类 号：U213.772[交通运输工程—道路与铁道工程]