黄土基底排土场动态稳定性研究

Loess floor dump is in the stability state under the action of large-scale load, water and other equivalent external force. When dump to the border as well as in the wet year, whether the dump slope can maintain a permanent stable under the action of blasting near working face, driving and other vibration power was placed in front of scientists. Through research approach combination of spot examination, theoretical analysis, experimental studies, numerical simulation and field application, the project analyzed the long-term coupling mechanism of the basal loess under static load, water, power and other complex factors; evolved rheological mechanism of the weak layer; studied the influencing factors and interrelation which affecting dynamic stability of loess floor earth-disposal site; set the judgement basis of loess floor earth-disposal site dynamic stability. Using finite element method to consider the influence of power effective stress、pore pressure dissipation and rheology of evolution weak layer on loess floor earth-disposal site dynamic stability, the re-enable abandoned height, slope angle and other parameters of loess floor earth-disposal site was simulated and designed. Through the experimental study of rheological properties, the strength characteristics of the different water content, pore pressure dissipation and compression characteristic of dump basal loess which met the design parameters, the long - term hierarchical evolution laws of basal loess and loess microstructure evolution process were obtained. Determining the evolution of dynamic mechanical properties of basal loess and revealing the landslide mechanism of loess floor earth-disposal site provide theory basis for dynamic stability control of loess floor earth-disposal site.

黄土基底排土场在大面积载荷、水等等效外力作用下处于稳定性状态，但排土场到界后在丰水年份、临近工作面放炮和行车等动力作用下能否保持永久性稳定，就摆在科研工作者面前。项目采用现场考察、理论分析、实验研究、数值模拟和现场应用相结合的研究方法，分析大面积黄土基底排土场在静载荷、水及动力等复杂因素的长期耦合作用下演化弱层的流变机理；研究黄土基底排土场长期稳定性的影响因素；建立黄土基底排土场动力与动态稳定性判据；采用有限元法，考虑动力有效应力、孔隙压力消散、演化弱层流变对黄土基底排土场动态稳定性影响。研究黄土基底排土场到界后重新启用的排弃高度、边坡角等参数以及到界后排土场基底黄土进行流变特性、不同含水量的强度特性、孔隙压力消散和压缩特性试验，得到基底黄土长期分层结构演化规律及黄土微观结构演化过程，确定基底黄土期力学性质的演变，揭示黄土基底排土场滑坡机理。为黄土基底排土场动态稳定控制提供理论基础。

露天矿排土场作为松散物料的主要处置场所，其稳定性对露天矿的安全生产期起着至关重要的作用。现阶段排土场稳定性分析均基于静力学理论，对于黄土基底型排土场，在受外载因素作用下，黄土基底如何变化、排土场可否长期处于稳定及能否重新启用等问题则有待解决。项目采用现场调研、理论分析、试验研究、数值模拟和现场应用等手段相结合的方法，研究黄土基底排土场长期稳定性的影响因素，在进行基底黄土流变特性、不同含水率强度特性、孔隙压力消散及压缩特性试验的基础上，得到基底黄土长期分层结构演化规律、黄土微结构演化过程及基底黄土孔隙压力消散规律，结合排土场孔隙压力消散特性提出消散度控制方程及孔隙压力消散控制方程，分析静载荷、水及动力等复杂因素耦合作用下黄土基底排土场演化弱层的流变机理，提出演化弱层的三个特性，即应力水平对应性、介质类型选择性和物理力学性质演变。充分考虑动力有效应力、孔隙压力消散、演化弱层流变对黄土基底排土场动态稳定性影响，并基于极限平衡法和孔隙压力消散规律首创性提出黄土基底排土场动态稳定性判据，为黄土基底排土场动态稳定控制提供理论基础。提出黄土基底排土场稳定性控制技术，即“分段排土，控制强度，分区推进，调整程序，监测监控，增大容量”，基于该技术，提出黄土基底排土场重新启用条件。该成果已在安太堡矿南排、西排，准格尔黑岱沟矿北排、西排及外排等排土场边坡治理中得到了合理有效地应用，并产生了良好的经济效益和社会效益，可推广至类似类型的排土场边坡应用中。