老顶初次来压步距的计算预测法

本文根据大量初次来压步距的统计和老顶“板”模型破断规律的研究,论述了老顶初次来压步距a_i的构成。它由反映其自身稳定性的步距准数l_m与反映工作面长度和开采边界影响的“边—长”系数W_i之积构成,即a_i=l_m·w_i。得出了工作面长度对老顶来压步距及其极限悬露面积的影响均呈w形曲线关系的结论。开采边界不同,其w形曲线也略有差异。据此,提出了常见的四种开采边界条件下来压步距的计算方法,以及利用实测步距推广到邻近工作面中去的换算方法。同时,对顶板分类提出应以步距准数l_m为指标,并用作w形曲线图法进行分类。     

倾斜长壁工作面老顶岩层破断规律的研究

本文利用弹性基础梁理论,研究了倾斜长壁工作面老顶岩梁的运动和破断规律,分别对仰斜开采和俯斜开采条件下老顶岩层断裂的位置和条件、老顶来压步距等进行了分析.研究表明,倾斜长壁开采时老顶岩梁的初次断裂过程有三种类型,并给出了相应的计算公式。同时分析了煤层倾角和顶板条件对老顶断裂和矿压显现的影响。     

房柱式开采的矿压显现规律及顶板监测

通过理论分析和现场实例，对房柱式采煤的矿压显现规律及其特点进行了探讨。研究表明，房柱式开采时直接顶呈悬顶式周期性垮落；老顶初次垮落步距较常规开采大，且失稳定然；矿压显现强烈，且受煤柱回收顺序的影响。根据现场实际，实施了以顶板垮落步距分析和顶板动态实测相结合的顶板稳定性监测，取得了较好的效果。     

三软煤层大采高综采围岩控制技术

根据三软煤层围岩力学性质,研究了直接顶与老顶的构成和直接顶、老顶初次来压与周期来压步距以及顶板压力的变化规律,提出了加大初撑力及时护顶等控制顶板运动显现的措施以及防止煤壁片帮和支架插底的技术措施并付之实践,取得了三软煤层大采高控制围岩的预期效果.     

三软煤层大采高综采围岩控制技术

根据三软煤层围岩力学性质,研究了直接顶与老顶的构成和直接顶、老顶初次来压与周期来压步距以及顶板压力的变化规律,提出了加大初撑力及时护顶等控制顶板运动显现的措施以及防止煤壁片帮和支架插底的技术措施并付之实践,取得了三软煤层大采高控制围岩的预期效果．     

采场老顶初次来压时的稳定性分析

本文用光弹试验、梁理论和几何分析法等力学方法,分析了采场老顶初次来压时镶嵌块体结构的稳定性问题,给出了老顶初次来压的失稳判据。     

《中国矿业大学学报》1993年总目录

第一期巷道与上部煤层间垂距Z的选择…………………………………………·陆士良 姜耀东 孙永联(l)放顶煤综采采空区“三带”的理论计算与观测分析……··邱志乾丁广骏左树勋 刘润身赵长春(8)极限分析与老顶初次来压步距计算…··‘…、…。…。……………·戴兴国 钱鸣高(17)两井定向测量后加测陀螺定向边的数据处理与精度分析………………………··、冯仲科陈于恒(24)监测网变形分析··。……………………………。……………………………刘忠海(爿)曲面磨光法及其在煤田隐伏构造预测中的应用…………………··、………… 许友志毛善…     

耿村煤矿综放开采覆岩移动和矿压显现规律研究

厚煤层综放开采矿山压力和围岩控制一直是综放开采研究的重点问题。基于义马矿区耿村煤矿特厚煤层综放工作面的地质采矿条件,采用数值模拟和现场矿压观测的方法,对综放工作面覆岩移动和矿压显现规律进行研究。结果表明:(1)综放工作面上方老顶形成"三铰拱"形砌体结构,该结构初次失稳和周期性失稳造成工作面初次来压和周期来压。老顶来压后,工作面前方支承压力趋于稳定,主要表现在最大应力集中系数和塑性区范围基本保持不变。(2)综放工作面顶板周期来压步距14.4~17.5 m,平均16.2 m,顶板来压动载系数1.81~2.04,平均1.92,顶板来压明显但较缓和。顶板来压期间支架时间加权平均工作阻力为其额定工作阻力的72.2%,选用ZF8600/18/35D型放顶煤液压支架合理。研究结果可为义马矿区综放开采围岩控制提供技术支撑。     

复杂条件下上提蹬空工作面矿压显现特征研究

为了解决蹬空对巷道围岩变形影响严重等问题,针对张集矿1410（1）工作面复杂的地质条件,采用计算机数值模拟（UEDC）系统和现场工程实践相结合的方法,对工作面推进不同距离时上覆岩层垮落形态、初次来压步距、周期来压步距、液压支架受力以及巷道围岩的变形特征进行研究。研究表明：工作面老顶初次来压步距约为32 m左右,周期来压步距约为16 m左右。工作面液压支架所需支撑的最大岩层高度约为25m。在工作面每天正常推进8m的情况下,工作面压架的危险性较小。     

软岩采场老顶破断的有限元模拟

将软岩采场老顶岩层视为支承于粘弹性基础上的薄板，设计了研究老顶破断的ＦＥＡＥＢＰ有限元模拟方法。该法能有效的模拟各种岩性参数、开采边界条件和各种几何尺寸的老顶岩层在开采过程中破坏的过程和结果，最终提供老顶的破坏形式、断裂步距、顶板下沉状态等分析数据，并对老顶来压的预测预报、选择合理的控顶措施提供依据。     

Impact of geo technical factors on strata behavior in longwall panels of Godavari Valley coal field-a case study

Understanding the cantilevers formed by thick, massive beds in the near-seam overburden above longwall panels and the associated loads and strata fracturing effects developed during caving(main and periodic weightings) are key elements for the successful implementation of longwalls. Such caving mechanisms rely on the geotechnical conditions within the panel. In India, the majority of longwall downtime and/or roof failures were caused by a lack of knowledge on overburden caveability, in particular when the main and periodic weightings will impact the face and longwall support selection to effectively mitigate such weightings. Godavari Valley Coal Fields is no exception as longwall faces were adversely affected due to the presence of thick, massive beds in the near-seam overburden at both Godavarikhani(GDK) 7 and 9 Incline mines. In contrast, overburden weightings were negotiated successfully in GDK10 A and Adriyala Longwall Project(ALP) mines by detailed geotechnical studies, the use of adequate longwall support capacities, and effective operational practices. Thirteen longwall panels with varying face width, at different depths have been extracted under massive sandstone beds of 18 m to28 m thickness at GDK 10 A and ALP mines. This study elucidates that the main roof weighting interval decreases with an increase in face width and attains a constant value with further increases in face width under the same geo-mining conditions. In addition, this study also concludes that with increases in face width, the periodic roof weighting interval decreases and shield loads increase. Similarly with increasing panel width to depth ratio, the main and periodic roof weighting intervals decrease but shield loads again increase. Lastly, the strata behaviour of the longwall face retreated along up-dip direction is demonstrated. The results of this paper improves the mechanistic understanding of the impact of face width,depth and main roof thickness on periodic weighting and associated roof control problems on the longwall face.     

工作面顶板周期来压灾变预测和拓扑预测

工作面顶板周期来压是矿井灾害之一．本文用灰色系统理论的灾变预测和拓扑预测对工作面顶板周期来压进行了研究,并利用义马跃进煤矿支柱载荷的观测数据和工作面顶板周期来压的关系对工作面顶板周期来压进行预测,得出了精度较高的预测结果,为工作面顶板周期来压的预测提供了新的思路．     

工作面顶板周期来压灾变预测和拓扑预测

工作面顶板周期来压是矿井灾害之一.本文用灰色系统理论的灾变预测和拓扑预测对工作面顶板周期来压进行了研究,并利用义马跃进煤矿支柱载荷的观测数据和工作面顶板周期来压的关系对工作面顶板周期来压进行预测,得出了精度较高的预测结果,为工作面顶板周期来压的预测提供了新的思路.     

单体支柱工作面顶板动态的监报

本文提出顶板动态监报应包括回采工作面局部冒顶的监报及顶板来压的预报这两个方面的观点。初步给出了局部冒顶监报指标的确定方法;重点探索了采用回采工作面来压综合判断指标来预报顶板来压的可能性。文中所给的回采工作面局部冒顶的监报指标及顶板来压预报指标所采用的系数,基于现场统计资料,或现场经验的数学处理结果。     

Relationship between water inrush from coal seam floors and main roof weighting

A water-resistant key strata model of a goaf floor prior to main roof weighting was developed to explore the relationship between water inrush from the floor and main roof weighting. The stress distribution,broken characteristics, and the risk area for water inrush of the water-resistant key strata were analysed using elastic thin plate theory. The formula of the maximum water pressure tolerated by the waterresistant key strata was deduced. The effects of the caved load of the goaf, the goaf size prior to main roof weighting, the advancing distance of the workface or weighting step, and the thickness of the waterresistant key strata on the breaking and instability of the water-resistant key strata were analysed.The results indicate that the water inrush from the floor can be predicted and prevented by controlling the initial or periodic weighting step with measures such as artificial forced caving, thus achieving safe mining conditions above confined aquifers. The findings provide an important theoretical basis for determining water inrush from the floor when mining above confined aquifers.     

不确定因素影响下的混凝土结构温度场仿真计算方法

混凝土结构前期仿真计算各控制参数存在着不确定性,若将其忽略,计算结果的准确性甚至温控方案合理性将受影响。根据这些不确定性因素具有区间分布特性且缺乏统计资料的特点,引入了区间数学理论,推导了相应的区间有限元公式。通过分析,在摄动理论和区间单调性理论的基础上,提出了所推导的区间有限元整体方程的近似"最窄"解区间的求解方法。考虑到实际工程中水管冷却的一些影响因素也存在不确定性,提出了考虑冷却方案区间变化的的水管冷却温度场迭代计算方法。利用Fortran语言编制了相应的区间有限元计算程序,对某现场非绝热温升实验块进行仿真计算,通过计算结果与实测数据的对比分析,验证了算法理论及程序的有效性和准确性。     

一种改进的Neville型有理式RCS数据插值算法

针对目标RCS数据的插值问题,在充分考虑RCS数据的相关性、插值数据的权重和计算舍入误差对插值结果影响的基础上,提出一种改进的Neville型有理式RCS数据插值算法.仿真结果表明,与传统Neville型有理式算法相比,改进算法降低了计算舍入误差和Runge现象对插值结果的影响,实现了目标RCS数据的高精度插值,为根据测量或计算的样本数据估计任意姿态和频率点的RCS数据提供了一种新的方法.