风沙区超大工作面开采的土地损伤规律及生态修复方法

Based on the characteristics of fast changes of land damage due to coal mining with super-large faces in windy and sandy region and the theories and methods such as mining subsidence, soil science, land science, surveying and mapping, the surface movement and deformation, full process of the surface cracks’ germination and growth and their space form, spatial and temporal change rules of soil and plants are studied by use of similar material models, numerical simulation and long, fixed stations in- situ. Monitoring methods of land damage due to coal mining with super-large faces are proposed. The mechanism of surface movement and deformation, the dynamic changes rules of surface cracks, soil and plant, and self-repair characteristics of surface environment are revealed. Comprehensive evaluation model of land damages is developed. According to the analysis of characteristics of land damages and based on pot and field experiments, principles and methods of ecological restoration of damaged land due to coal mining with super-large faces are presented. Two kinds of restoration methods for two typical damage characteristics are developed: isolation and revegetation for uniform settlement regions, and crack-filling and induced revegetation for non-uniform settlement regions. The results provide a theoretical and technical support for harmonic mining between resources and environment in ecological fragile region.

针对风沙区超大工作面高强度煤炭开采对土地影响剧烈、演变迅速的特点，利用开采沉陷学、土壤学、土地科学、测绘学等理论，通过长期、定位、全过程的地表移动、裂缝、水土环境、植被等野外监测并结合相似材料模型及数值模拟试验，研究风沙区煤炭开采地表移动变形、地表裂缝发生发育全过程及地下空间形态、水土环境（重点是土壤含水、入渗等）和地表植被的时空变化规律，提出风沙区超大工作面开采土地损伤的监测方法，揭示地表移动变形机理和地表裂缝、水土环境、植物生态随开采的动态变化规律及自修复的时效特征，构建土地损伤综合评价模型。在深入分析土地损伤特征的基础上，通过室内盆栽和野外田间试验，提出超大工作面高强度开采的生态修复的原理与方法，尤其是提出均匀沉陷区的封闭植被恢复方法和非均匀沉陷区的裂缝充填加人工诱导植被修复方法，为生态脆弱矿区的资源与环境协调开采提供理论和技术支撑。

针对风沙区超大工作面高强度开采对土地影响剧烈、演变迅速的特点，综合利用测绘学、开采沉陷学、土壤学、土地科学等理论进行了系统研究，选择神东矿区补连塔某超大工作面布设地表移动观测站，设计地表裂缝、土壤水分、土壤入渗、地表植被参数等监测方案，研究风沙区煤炭开采地表移动变形、地表裂缝发生发育全过程与地下空间形态、水土环境（重点是土壤含水、入渗等）、地表植被的时空变化规律，以及煤炭开采对土壤酶活性、土壤微生物的影响，从开采损伤的全过程出发，对神东矿区典型工作面地表环境的演变特征进行了动态观测。探讨了神东矿区地表移动变形规律及其共性，定量分析了高强度大工作面开采技术条件下地表沉陷变形的自修复特征；发明了动态地裂缝发育规律的监测方法，发现了动态地裂缝快速闭合的自修复特征，建立了其发育周期T的数学模型，揭示了边缘地裂缝的发育过程及其分布特征；利用相似材料模型以及数值模拟试验，阐释了动态地裂缝呈现双周期发育特征力学机理。通过典型地裂缝的充填开挖，利用GPR以及lensphoto近景摄影测量技术，探明了地裂缝在浅地表地下空间的扩展形态；通过典型样区土壤取样，揭示了土壤理化性质的变化特征；通过对植被参数以及土壤结皮的研究，探讨了开采对植被以及地表结皮的影响。并基于上述研究，构建了风沙区土地损伤的自修复能力评价模型，对超大工作面开采条件下沉陷区自修复能力进行了评价，认为应进行差异化修复，提出了风沙区“分区”差别化的生态修复模式、边采边复方法以及“馅饼式”土地生态修复原理与技术，为生态脆弱矿区的资源与环境协调开采提供理论和技术支撑。