多层土工织物加固填土路基的特征分析

针对传统的极限平衡分析法不能较好地反映土工织物与土间的变形协调关系,采用非线性有限元法探讨了多层土工织物加固填土路基的变形与破坏特征.结果表明,在假定土工织物与土之间无相对位移条件下,土工织物的铺设层数对路基破坏面的位置影响不明显,路基的潜在破坏面近似为一通过坡趾处的圆弧面;离路基顶面越近,土工织物上的轴力越小;土工织物位于路基中部作用较大,而位于路基坡脚的轴力大为减小;铺设土工织物后,路基的稳定性提高较大,铺设层数越多,路基的安全系数增幅越大;铺设于路基体内的土工织物对减小地基体内的水平位移作用有限,实际工程中需采用其他措施约束地基体内水平位移的处理.     

Using a Fluid–Solid Coupled Numerical Simulation to Determine a Suitable Size for Barrier Pillars When Mining Shallow Coal Seams Beneath an Unconsolidated,Confined Aquifer

Barrier pillars are an effective and fundamental measure to prevent water inrush when mining shallow coal seams under an unconsolidated, confined aquifer. Based on the complex geological and hydrogeological conditions in the southern area of the Qidong coal mine, the no. 6₁ coal seam there was selected for a research demonstration. A fluid–solid coupled numerical simulation was carried out using the universal distinct element code. The hydraulic pressures and seepage rates in overlying strata were analyzed for two mining cases, near the aquifer and near the fault. The results showed that the degree of interconnection between the bed-separated and vertical fractures, and increases in hydraulic pressures and seepage rates in overlying strata were key factors in predicting potential water inrush when mining shallow coal seams under an unconsolidated, confined aquifer. Combining the numerical simulation results with China’s coal mining requirements, the no. 6₁ coal seam can be mined up to 90 m beneath the unconsolidated, confined aquifer, which limits mining to an altitude of ?509.36 m. The width of the barrier pillar should be 30.7 m near the fault.     

边坡稳定性分析方法简述

对边坡稳定性的极限平衡法与有限元方法进行了对比分析,并将这两种方法相结合考察边坡的稳定性,这是边坡稳定性分析的一个重要发展方向.根据有限元计算得到的近似真实应力场,利用数学手段(如动态规划法)计算得到边坡的最小安全系数及其相应的临界滑裂面的确切位置,还有待推出较成熟的商业计算软件.     

考虑温度应力影响的立井井壁强度设计方法

 基于大量破裂井筒工程实例,对立井设计规范方法进行验证,发现规范计算方法的判断结果与实际情况相差较大。分析表明,现行立井设计规范尚未考虑温度应力的影响,而温度差会对立井体内的应力与应变产生影响是客观事实,因此有必要对其进行修正。基于弹性理论,推导考虑温度应力影响的立井强度设计计算公式,分析公式的数学特征,考察不确定性因素及提出修正思路。鉴于该问题的复杂性,建议进行更深入的研究与探讨,以便提高规范计算方法的科学性、合理性与有效性。