摘要
为了揭示承载河道下高大内排土场的蠕变沉降规律,以某露天煤矿内排土场为研究对象,结合排土场回填体的三轴蠕变试验和地表沉降监测,反演排土场碾压区砂砾石土和非碾压区细粒土质砂的蠕变参数,建立了内排土场边坡三维模拟数值模型。Burgers黏弹性蠕变模型模拟结果表明:内排土场碾压区和非碾压区2020—2029年的蠕变沉降和水平变形均达到收敛状态,经历了初期加速蠕变、中期减速蠕变和后期收敛蠕变3个阶段;蠕变沉降量随距坡肩距离增大而减小,碾压区河道外侧边界正下方及碾压区与非碾压区分界位置2个监测点的蠕变沉降收敛于0.33 m和0.40 m,沉降变形量小且近似均匀,对河道运营和坝体安全的影响较小;非碾压区坡肩处2020—2029年竖直和水平蠕变量为7.43 m和8.92 m,最大蠕变发生在非碾压区中部及中上部台阶处,是回填土蠕变滑坡的重点监测和预防区域。通过建立排土场沉降蠕变理论模型,得到了填方土蠕变沉降方程和下沉速度系数,理论模型与数值模拟的蠕变沉降量具有较好的一致性,验证了数值模型的合理性。
In this study,to understand the creep settlement,the authors established a model of a large inner dump with a river channel,and the waste dump of an open-pit coal mine was taken as the engineering background.Through an inversion analysis using the three-axil creep experiment in the lab and surface subsidence measurement in the field,the creep parameters of the sandy gravel soils in a compact area and the fine-grained soil sand in a non-compact area were determined.The Burgers constitutive model numerical simulation results show that:(1)In both the non-compact area and compact area of inner dump in 2020-2029,the vertical and horizontal of the dump is convergent.The process can be classified into three stages:preliminary accelerating creep,mid-term decelerating creep,and late converging creep.(2)The creep settlement increases with decreasing the distance from the slope edge.The final convergence creep of measuring points below the outer boundary of the river and at the boundary between rolling and non-rolling area in the compact zone is 0.33 m and 0.40 m,respectively,which is insignificant and uniform and shows no impact on river channel operation and dump stability.(3)The slope edge in the non-compact zone shows the vertical and horizontal convergence of 7.43 m and 8.92 m.The largest deformation occurs at the middle to top positions on the dump slope,which is the most vulnerable area for the slope slide and the most important area for deformation monitoring.A theoretical model of dump creep settlement was developed to validate the numerical model results.The creep settlement equation and the subsidence velocity coefficient were obtained.Good agreement on creep settlement between the theoretical and numerical results was obtained,indicating the validity of the numerical model.
作者
曹博
黄云龙
张院生
汪帅
刘士晨
刘光伟
CAO Bo;HUANG Yun-long;ZHANG Yuan-sheng;WANG Shuai;LIU Shi-chen;LIU Guang-wei(College of Mining,Liaoning Technical University,Fuxin 123000,Liaoning,China;Academy of Railway Sciences(Shenzhen)Research and Design Institute Co.,Ltd.,Shenzhen 518054,Guangdong,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2022年第3期1306-1314,共9页
Journal of Safety and Environment
基金
国家自然科学基金项目(51974144)。
关键词
安全工程
内排土场
蠕变阶段
蠕变模型
数值模拟
反演分析
safety engineering
internal dumping site
creep stage
creep model
numerical simulation
back analysis
