为研究厚松散层薄基岩煤层开采条件下,不同基载比对煤矿安全开采的影响,以某矿为工程背景,采用理论分析和数值模拟的研究方法,研究不同基载比情况下回采工作面采动覆岩破坏规律,分析不同基载比开采对顶板稳定性的影响,得出厚松散层薄基岩煤层安全开采的基载比界限.研究得出:煤层埋深一定情况下,安全开采的极限基载比为0.08,当基载比小于0.08时,顶板基岩难以形成有效的承载结构而失稳,此时应提高支护强度,加强顶板管理,保证工作面安全开采.

We construct a two-level dual-sourcing supply chain model in traditional supply chains and B2B electronic markets,where traditional supply chains are susceptible to disruption risks.The different procurement models are compared and the analytical conditions of optimal procurement strategies are obtained.We also analyze the effects of disruption probability and market liquidity on procurement strategies.The results of our analysis show that significant profit improvement can be achieved in B2B electronic markets and the third-party B2B markets procurement model is the best.