基于位移与应变场的滑坡体时空形变特征研究  

Spatial and Temporal Characteristics of the Deformation Field of Landslide Mass Based on Displacements and Strain Fields

作　　者：曹冬冬 CAO Dongdong(China Coal Xi’an Design Engineering Co Ltd,66 North-Yanta Road,Xi’an 710054,China)

机构地区：[1]中煤西安设计工程有限责任公司,西安市710054

出　　处：《大地测量与地球动力学》2023年第5期498-504,共7页Journal of Geodesy and Geodynamics

摘　　要：以山西省沁水县里必煤矿附近一处滑坡体为例开展近1 a的高精度变形监测。通过小变形条件和有限变形条件下的应变,计算研究目标滑坡体在滑动前、滑动期间和滑动后不同阶段形变场的时空特征。通过分析最大、最小主应变场发现,锚索加固之前里必煤矿支挡墙对早期滑坡体前缘的加速滑动仍有40%左右的抑制作用。滑坡体前缘与支挡墙之间的挤压冲击作用具有明显的时空不均匀特征,二者之间的主压应变方向与强度存在明显的时空变化。滑坡体的局部强应变异常可能是监测目标结构性破坏的重要标志,研究区域830 m等高线位置于2020-12-13出现的局部强拉张变形与斜坡上一条10~20 cm宽的横向开裂具有良好的对应关系。在滑坡体整体运移与相对变形都较小的稳态背景下,斜坡表面裂缝的发育表明滑坡的破坏仍在持续。滑后调整阶段,滑坡体整体特别是发生滑动的后缘变形模式相当复杂,同时经历了相近强度的压缩变形与拉张变形。滑坡体历经3个月仍没有完全归于稳定,仅在后缘中段初步形成了与原主滑动轴方向相似的局部滑动趋势。We take a landslide near Libi coal mine in Qinshui county,Shanxi province as an example to carry out high-precision deformation monitoring for almost one year.By constructing strain models under small deformation conditions and finite deformation conditions,we study the spatial and temporal characteristics of the deformation field of the target landslide at different stages before,during and after sliding.Through analysis of the maximum and minimum principal strain fields,we find that the retaining wall of Libi coal mine before anchor cable reinforcement still has about 40%inhibitory effect on the accelerated sliding of the early landslide front.The compressive impact between the landslide front and the retaining wall has obvious spatiotemporal inhomogeneity,that is,the direction and strength of principal compressive strain between them have obvious spatiotemporal variations.The local strong strain anomaly of the landslide may be a significant indicator of the structural failure of the monitoring target.The local strong tensile deformation at 830 m contour in the study area on December 13,2020,has good correspondence with a transverse 10-20 cm wide cracking on the slope.Under the steady-state background where the overall migration and relative deformation of the landslide are small,the occurrence and development of cracks on the slope surface indicate that the failure and development of the landslide are still continuous.In the post-sliding adjustment stage,the deformation mode of the whole landslide,especially the trailing edge where sliding occurs,is quite complex,and it also experiences compression deformation and tension deformation with similar strength.The landslide,after 3 months,was not completely stable,and only a local sliding trend like the direction of the original main sliding axis was initially formed in the middle part of the trailing edge.

关 键 词：滑坡 小变形 有限变形 最大、最小主应变 时空特征 

分 类 号：P258[天文地球—测绘科学与技术]