胶结充填体-顶板系统稳定性研究

在胶结充填采矿法中，胶结充填体弹性系数和其不接顶高度是空区顶板安全的重要影响因素。基于柔性支护原理，把顶板变形分为两个阶段：顶板在覆岩自重应力作用下产生挠曲变形；顶板与胶结充填体接触后共同承载顶板覆岩自重应力；并据此分别建立了力学模型。以广西盘龙铅锌矿为工程分析实例，研究在不同胶结充填体弹性系数和不接顶高度条件下顶板挠度的变化规律。结果表明：当胶结充填体弹性系数k≥0.1 GN/m3时，不接顶高度h是影响顶板挠度的主要因素，当胶结充填体弹性系数k较小时，弹性系数k是影响顶板挠度的主要因素；当k≥0.1 GN/m3且h≤300 mm时，胶结充填体能有效控制顶板岩层移动和降低储存在其中的应变能。现场勘探结果与理论计算基本吻合，验证了研究成果的可靠性。

Stability analysis of cemented filling body and roof

Elastic coefficient (k) of cemented filling materials and roof-untouched filling height (h) are key impact factors on the roof stability in cemented filling mining. Based on the principle of flexible supporting, roof deformation was divided into two stages, i.e., under the gravity stress of overburden rock and the roof presented flexural deflection. Both roof and cemented filling materials under the gravity stress of overburden rock were contacted with each other. Accordingly, mechanical models were established for each stage. Panlong Lead-Zinc deposit in Guangxi was selected as the case study to investigate the characteristics of roof deflection with different roof-untouched filling heights and elastic coefficients. The results show that roof-untouched filling height is the dominant factor which affects the deflection of the roof when k≥0.1 GN/m3, and the elastic coefficient would play the key role when k≤ 0.1 GN/m3. Cemented filling materials can effectively control the movement of roof strata and reduce the strain energy stored in roof strata when k≥0.1 GN/m3 and h≤300 mm. The theoretical analysis results are consistent with the in-situ drilling, indicating the feasibility of this study.