高级检索

基于黏弹性理论的软基底排土场周边地表变形预测方法

Prediction method of surface deformation around soft base dump based on viscoelastic theory

  • 摘要: 针对软弱基底排土场堆载引起的周边地表变形问题,从层状弹性体系理论出发,深入探讨了变形现象的机理与影响。通过运用微积分思想,将排土场荷载微分,并对周边土体的作用进行了叠加,结合基底表面应力边界条件和层间界面连续条件,引入了广义Kelvin三轴蠕变模型,以更精确地描述软弱基底的变形特性,从而推导出一种具有流变特性的黏弹性基底排土场周边地表变形解法。选择了本钢集团歪头山铁矿下盘排土场作为案例进行分析,通过计算预测排土场堆载作用下层状黏弹性基底地表变形情况,得到了一系列关于地表变形的定量数据,可以看出排土场周边高铁线墩台沉降uz和相邻墩台沉降差∆uz会随着时间演化逐渐增大,后趋于平缓;排土场与高铁线并行段沉降为2.08 mm,高铁离开排土场并行范围最大相邻墩台沉降差为0.006 mm/m。与现场监测数据进行对比分析后发现,地表变形解析结果与实际情况基本吻合,从而验证了黏弹性基底排土场周边地表变形解法的有效性和合理性,且解析数值均低于规范阈值。在进一步的研究中,通过对影响排土场周边地表变形因素(边坡高度、边坡角、地表距离和时间)分析,发现了一些重要的规律性特征:排土场距离坡脚越远,周边地表变形越小,呈现出明显的反比例关系;边坡高度和角度越大,地表变形越明显;地表变形随着排土场施工时间演化,在短时间内达到峰值,之后趋于稳定。研究结果为理解软弱基底排土场堆载引起的地表变形规律提供了重要的理论依据和实践指导,同时,所提出的解决方案为类似工程项目中的地表变形管理提供了新的思路和方法,有望在工程实践中取得积极的应用效果。

     

    Abstract: Addressing the challenge of surrounding surface deformation induced by soil discharge field pile loads in weak substrates, this study delves into the mechanisms and impacts of such deformations extensively, drawing from the theory of laminar elastic systems. Employing calculus principles to differentiate the soil discharge field load and overlay the effects on the surrounding soil, coupled with considerations of substrate surface stress boundary conditions and interlayer interface continuity, the study introduces the generalized Kelvin triaxial creep model to more precisely characterize the deformation traits of weak substrates. Consequently, a methodology for addressing peripheral ground surface deformation of viscoelastic substrate soil discharge fields with rheological characteristics is derived. For the investigation, the discharging yard of the lower plate of Crooked Head Mountain Iron Mine of Bensteel Group is selected as a case study. A series of quantitative data is obtained through calculations and predictions of surface deformation on layered viscoelastic substrates under pile load actions in the discharging yard. It is observed that the settlement of piers around the discharging yard and the variation in settlement between neighboring piers gradually increase with time evolution, eventually reaching a stable state. Furthermore, in parallel sections, the settlement of the discharging yard and high-speed rail lines is 2.5 and 2.3 times respectively. The settlement in the parallel section is measured at 2.08 mm, with the maximum settlement difference of adjacent piers being 0.006 mm/m. Comparative analysis with on-site monitoring data indicates close alignment between the surface deformation analysis results and actual conditions, thereby validating the efficacy and soundness of the viscoelastic substrate's surface deformation solution around the discharging field. Notably, the analyzed values remain below normative thresholds. Further examination reveals key patterns in factors influencing surface deformation around earth displacement fields (such as slope height, angle, surface distance, and time). Notably, the distance of the earth displacement field from the slope's foot inversely correlates with surrounding surface deformation, while greater slope height and angle exacerbate deformation. Additionally, surface deformation evolves over construction time, peaking quickly before stabilizing. Overall, the findings furnish a crucial theoretical underpinning and practical guidance for comprehending and mitigating surface deformation caused by soft substrate disposal site pile loads. The proposed solutions offer novel insights and methods for managing surface deformation in analogous projects, with the potential for positive application in engineering practice.

     

/

返回文章
返回