讨论不同特征参数的变化规则与扩张深度的土壤取坡度的讨论
Chaozheng Shen1, Xueyun Miao2,3, Yongqiang Li4
1School of Transportation Engineering, Nanjing University of Technology, Nanjing, 210009, China.
Scientific reports
|March 31, 2025
概括
膨胀的土壤对土工造成风险,原因是土壤膨胀和收缩. 这项研究表明,斜坡的损坏主要发生在约1.0米深处,土壤强度最低的地方.
科学领域:
- 地质技术工程 地质技术工程
- 土壤力学 土壤力学
背景情况:
- 膨胀性土壤表现出显著的体积变化 (潮湿膨胀和干燥收缩),影响土壤工程的稳定性,特别是悬崖斜坡.
- 广土壤的工程性质是土壤面积土壤工程中的一个关键挑战.
研究的目的:
- 研究广土壤与深度相关的工程性质.
- 探索干燥散装重量,不受限制的压力强度和三向膨胀力的变化规则,以及坡的深度.
主要方法:
- 实地考察三个代表性的拉菲尔坡站点.
- 室内实验室测试包括干散重量,不受限制的压力强度和三向膨胀力测量.
- 扩张力和体积变化与深度的分析.
主要成果:
- 水平扩张力在延伸和近距离方向上是一致的;垂直扩张力大约是水平的两倍 (比率~0.5).
- 表面土壤指标显示出很高的变化. 在0.5-1.0米深度之间,干密度低,膨胀/收缩显著,不受限制的压力强度达到最低.
- 膨胀力和体积指标稳定在2.0米深以下.
结论:
- 对广的土壤裂变斜坡的损害集中在1.0米高的上层.
- 这种损害归因于土壤无法适应应力变化和自然大气力量.
相关概念视频
Design Example: Maintaining Level of an Embankment
42
Constructing a roadway embankment over uneven terrain requires precise leveling to ensure stability and proper drainage. Surveyors use a leveling instrument and staff to calculate ground elevations and determine the required fill material at each point along the embankment alignment.The process begins by positioning a leveling instrument near a benchmark with a known elevation. A backsight reading establishes the instrument height, which serves as a reference for subsequent measurements. A...
42
Taping Over Different Ground Profiles
19
Taping over varying ground profiles requires careful adaptation to achieve accurate measurements. On smooth, level ground with minimal vegetation, the tape can rest directly on the ground. Here, the taping team, typically consisting of a head and a rear tapeman, coordinates their positions with clear communication. The rear tapeman holds the tape at the starting point and guides the head tapeman toward a range pole placed beyond the endpoint, using hand or voice signals to ensure alignment.On...
19
Design Example: Design of an Irrigation Channel
41
Trapezoidal channels are widely used in irrigation systems due to their cost-effectiveness and efficiency in conveying water. Trapezoidal channels feature a flat bottom and sloping sides, making them stable and easier to construct compared to other shapes. The bottom width and side slope ratio are determined based on the required flow capacity and site conditions. The side slope is kept gentle for unlined channels to prevent soil erosion.Hydraulic parameters in channel design include the flow...
41
Expansion and Contraction in Masonry Walls
350
Masonry walls are subject to slight expansion and contraction due to variations in temperature and moisture. Thermal movement in masonry is relatively straightforward to measure and plan for. On the other hand, moisture movement poses more of a challenge. New clay masonry units typically absorb water and expand over time under normal environmental conditions. Conversely, new concrete masonry units tend to shrink as they lose the excess moisture acquired during their production process.
To...
To...
350
Uniform Depth Channel Flow: Problem Solving
43
To calculate the flow rate for a trapezoidal channel, first, identify the bottom width, side slope, and flow depth of the channel. The cross-sectional area (A) corresponding to the depth of flow (y), channel bottom width (B), and side slope (θ) is determined by:Next, calculate the wetted perimeter, which includes the bottom width and the sloped side lengths in contact with the water. Using the values of the cross-sectional area and the wetted perimeter, determine the hydraulic radius by...
43
Uniform Depth Channel Flow
50
Uniform depth channel flow keeps fluid depth consistent along channels such as irrigation canals. In natural channels, such as rivers, approximate uniform flow is often assumed. This condition occurs when the channel’s bottom slope matches the energy slope, balancing potential energy lost from gravity with head loss due to shear stress. This balance prevents depth changes along the channel length, resulting in a steady, uniform flow.Uniform flow in open channels with a constant cross-section...
50


