不同含石量宕渣路基压实特性

胡朋¹，迟连阳^1*，王琨¹，单衍勇²，宋志超²，杜海伦³，管清泳³

1.山东交通学院交通土建工程学院，山东 济南  250357；2.山东东方路桥建设有限公司，山东 临沂  276002；

3.山东舜都路桥工程有限公司，山东 潍坊  262200

摘要：为研究不同含石量（石在宕渣中的质量分数）宕渣的最佳压实振动频率及动力响应，采用离散元软件EDEM中的接触模型建立多组宕渣路基压实模型，振动频率分别为28、30、34、40 Hz，含石量分别为60%、70%、80%，分析颗粒轨迹、总应力及速度变化等。结果表明：1）含石量分别为60%、70%、80%的宕渣最佳振动频率分别为34、30、40 Hz。2）破碎率随含石量和振动频率的增大而增大；含石量相同时，压实含可破碎颗粒宕渣的孔隙率普遍小于含不可破碎颗粒的宕渣。3）粒径为3、30、70 mm的活跃度分别为0.098、0.716、29.372，粒径为70 mm的大颗粒活跃度较低，粒径为30 mm的颗粒活跃度较高，粒径为3 mm的小颗粒活跃度最高。4）压实过程中，按颗粒平均总应力、颗粒平均速度的变化主要分为塑性压实、工况过渡、压实后期3个阶段。5）在塑性压实阶段时，宕渣颗粒平均总应力较小，以塑性变形为主，振动板和宕渣间的接触力较小；在工况过渡阶段时，振动板与宕渣间的接触力和颗粒平均总应力突变；在压实完成阶段时，宕渣颗粒以弹性变形为主，形成良好的骨架密实结构，颗粒平均总应力较大。6）在塑性压实阶段，颗粒速度不稳定且较低，至压实完成阶段形成骨架密实结构，大、小颗粒相对位置变化较小，大颗粒夹带小颗粒随振动板共同振动，平均速度变化较小。7）颗粒平均速度和平均总应力的阶段性相同，且相同含石量在同一振动频率下的阶段持续时间相同；击实频率接近宕渣固有频率时，颗粒快速达到稳定状态，压实效果最佳。

关键词：宕渣；路基；离散元；击实试验；振动频率；含石量

Compaction characteristics of slag subgrade with different rock content

HU Peng¹, CHI Lianyang^1*, WANG Kun¹, SHAN Yanyong², SONG Zhichao², DU Hailun³, GUAN Qingyong³

1.School of Civil Transportation Engineering, Shandong Jiaotong University, Jinan 250357, China;

2.Shandong Dongfang Road and Bridge Construction Co., Ltd., Linyi 276002, China;

3.Shandong Shundu Road and Bridge Engineering Co., Ltd., Weifang 262200, China

Abstract: To study the optimal compaction vibration frequency and dynamic response of different stone content in tailings slag, multiple compaction models for tailings roadbed are established using the contact model in the discrete element software EDEM. The vibration frequencies are set at 28, 30, 34, and 40 Hz, with stone contents of 60%, 70%, and 80%. The analysis focuses on particle trajectories, total stress, and velocity variations. The results indicate that: 1) The optimal vibration frequencies for tailings slag with stone contents of 60%, 70%, and 80% are 34, 30, and 40 Hz, respectively. 2) The crushing rate increases with the rise of stone content and vibration frequency; for the same stone content, the porosity of the compacted mixtures containing crushable particles is generally lower than that of the mixtures containing non-crushable particles. 3) The activity of particles with sizes of 3, 30, and 70 mm is 0.098, 0.716, and 29.372, respectively; the activity of larger particles (70 mm) is lower, while the activity of medium-sized particles (30 mm) is higher, and the smallest particles (3 mm) have the highest activity. 4) During the compaction process, based on the changes in average total stress and average particle velocity, the process is mainly divided into three stages:plastic compaction, working condition transition, and completion of compaction. 5) In the plastic compaction stage, the average total stress of tailings particles is low, predominantly undergoing plastic deformation, with small contact forces between the vibration plate and the tailings; during the working condition transition stage, there is a sudden change in contact forces between the vibration plate and tailings, as well as in the average total stress of the particles; in the completion stage, tailings particles underwent primarily elastic deformation, forming a well-structured dense skeleton with a higher average total stress. 6) In the plastic compaction stage, the particle velocity is unstable and low, while in the completion stage, a dense skeletal structure is formed, with little variation in the relative positions of large and small particles; large particles carry small particles and vibrate together with the vibration plate, resulting in minor changes in average velocity. 7) The phases of average particle velocity and average total stress are consistent, and for the same stone content at the same vibration frequency, the duration of the phases is the same; when the impact frequency approached the inherent frequency of the slag, the particles quickly reach a stable state, resulting in the best compaction effect.

Keywords: slag; subgrade; discrete element; compaction test; vibration frequency; stone content