在列车载荷下,粗粒土壤填充剂的粉碎工艺的演变
Qiyun Wang1, Jiajun Zeng2, Qingqing Shen1
1College of Civil and Construction Engineering, Hunan Institute of Technology, Hengyang, 421002, China.
Scientific reports
|January 3, 2025
概括
这项研究模拟了火车负载下的粗粒度土壤中的颗粒破裂,预测了尺寸分布的演变. 这项研究为铁路底层建设和维护提供了洞察力.
科学领域:
- 地质技术工程 地质技术工程
- 土壤力学 土壤力学
- 铁路工程 铁路工程是指铁路工程.
背景情况:
- 颗粒碎裂对用于基层建筑的粗粒度土壤的工程性能产生重大影响.
- 现有的研究缺乏在动态负载下粒子大小分布演变的预测模型.
- 了解颗粒破裂对于铁路次级的长期稳定性和维护至关重要.
研究的目的:
- 为了研究模拟火车载荷的粗粒度土壤中颗粒破裂的进化行为.
- 开发一个粒子大小分布演变的预测模型.
- 分析动态应力,加载频率和振动对粒子碎片化的影响.
主要方法:
- 模拟使用MTS加载系统对粗粒度土壤填充物的动态列车负载效应.
- 分析颗粒破裂的宏观和微观特征.
- 使用ZHU连续分级曲线方程建立粒子大小分布的预测模型.
- 为破裂率指数推导一个积分表达式.
主要成果:
- 颗粒破裂模式包括在不同的负载条件下破裂,碎片化和研磨.
- 开发的分级预测模型准确地捕捉了粒子大小分布的演变.
- 断裂率指数有效地描述了铁路地下土壤中的颗粒断裂.
- 在100万个加载周期后,变形和颗粒破裂稳定,在测试条件下,破裂指数低于1.1%.
结论:
- 这项研究提供了一种经过验证的模型,用于预测在火车载荷下粗粒度土壤中粒子大小分布的演变.
- 衍生出的断裂率指数是铁路子级别颗粒断裂演变的可靠指标.
- 结果为优化铁路底层建设和维护实践提供了理论和实验基础.
相关概念视频
01:23Behavior of Concrete Under Compressive Load
112
Concrete exhibits specific behaviors under different compressive loads. Understanding this is crucial for understanding its structural integrity. When concrete undergoes uniaxial compression, it tends to develop cracks that run parallel to the direction of the force. These parallel cracks stem from localized tensile stresses that occur perpendicular to the compression direction. Additionally, angled cracks may appear due to the formation of shear planes.
As the concrete specimen fractures under...
As the concrete specimen fractures under...
112
01:23Abrasion Resistance of Concrete
80
Abrasion resistance is an essential characteristic of concrete that determines its durability and longevity under various wear conditions. Concrete surfaces are vulnerable to different types of abrasion. For instance, surfaces may wear down due to the constant movement of vehicles or be eroded by solids carried in water, as seen in concrete canal linings. Specific tests are conducted to measure the abrasion resistance of concrete.
One such test is the revolving disc test, where three plates...
One such test is the revolving disc test, where three plates...
80
01:22Compacting Factor test
84
The compacting factor test is a method used to assess the workability of concrete. It is especially suitable for concrete mixes containing aggregates up to one and a half inches in size. This test involves specialized equipment consisting of two truncated cone-shaped hoppers and a cylinder, all with polished interior surfaces to minimize friction.
The procedure begins by placing concrete into the upper hopper without any compaction. Once filled, the bottom door of this hopper is opened,...
The procedure begins by placing concrete into the upper hopper without any compaction. Once filled, the bottom door of this hopper is opened,...
84
01:29Additives and Fillers in Concrete
60
Additives and fillers are integral to enhancing the properties of concrete. Pozzolans and blast-furnace slag are additives or admixtures due to their reactions with calcium hydroxide released during cement hydration. Fillers, which are finely ground and similar in fineness to Portland cement, improve concrete attributes such as workability density, and reduce capillary bleeding or cracking. Some fillers possess hydraulic properties or participate in benign reactions within the cement paste.
The...
The...
60
01:24Design Example: Aggregate Gradation
81
The right type and quality of aggregates are crucial for concrete as they significantly influence its properties, mix proportions, and cost-effectiveness. If different sources are available for sand, the commonly used fine aggregate in concrete, the selection of sand is primarily based on its gradation.
The grading, or particle-size distribution, of sand is determined using sieve analysis, with standard sizes ranging from 150 μm to 10 mm (ASTM No. 100 sieve to 3⁄8 in. sieve). Sand is...
The grading, or particle-size distribution, of sand is determined using sieve analysis, with standard sizes ranging from 150 μm to 10 mm (ASTM No. 100 sieve to 3⁄8 in. sieve). Sand is...
81
01:22Creep in Concrete
97
Creep refers to the time-dependent increase in strain under a sustained load, excluding other time-dependent deformations associated with shrinkage, swelling, and thermal expansion in concrete. The primary mechanism behind creep involves the loss of physically adsorbed water from the calcium silicate hydrate within the hydrated cement paste. This process is further exacerbated by concrete's non-linear stress-strain relationship, microcrack development in the interfacial transition zone, and...
97