共查询到20条相似文献，搜索用时 453 毫秒
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Yang Sen Hua Xinzhu Yang Peng Liu Xiao 《Geotechnical and Geological Engineering》2021,39(7):5161-5172
Geotechnical and Geological Engineering - In order to determine the reasonable empty roof distance during roadway excavation, a mechanical model of the direct roof rock beam was established, and... 相似文献
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Geotechnical and Geological Engineering - This study investigates the influence of pre-existing discontinuities on the roof breaking behaviors under Longwall (LW) mining condition. Taking the... 相似文献
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First Joint meeting of the Geological Society of China （GSC） and the Geological Society of America （GSA） Brought together by the GSA International Section Chengdu, China in 17-19 June 2013. The abstracts are available online and can be downloaded for free. 相似文献
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在充分掌握地质勘探资料的基础上,利用井下物探和钻探等技术,对鄂尔多斯盆地蒙陕矿区深埋煤层首采工作面顶板水文地质条件进行了深入研究。结果表明,31101工作面顶板导水裂缝带范围内共发育三层含水层,从下往上依次为3-1煤顶板含水层、2-1煤顶板含水层和直罗组下段含水层;富水区域主要分布于2-1煤层顶板到直罗组下段岩层之间,岩性为中粒砂岩、中粗粒砂岩。切眼附近和旧回撤通道附近钻孔涌水量和水压波动较大,这两个区域顶板水富水不均一性较明显;中间位置顶板含水层发育较稳定,钻孔涌水量和水压也相对稳定,富水性比较均一。井下物探在切眼附近和旧回撤通道附近圈定的低阻异常区,主要由地层岩性和富水性等引起。 相似文献
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淮南矿区煤层为石炭二叠纪煤层,13-1煤属下石盒子组,煤层全区稳定,平均厚度为3．5m。由于该区视电阻率曲线在砂岩及煤层反映为高电阻率,而泥岩电阻率相对平缓,针对这个特点,利用约束稀疏脉冲反演方法,结合地震数据,重构富含顶底板砂泥岩信息的波阻抗曲线,得到了联井波阻抗剖面及煤层顶板属性切片图,该成果图可清晰反映13—1煤层及顶板以上10m范围内的砂、泥分布。通过该实例的应用,对如何建立地质模型、重构波阻抗的方法、子波估算方法及稀疏脉冲反演中的A值的选择等几个重要环节进行了剖析。 相似文献
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煤层顶板断裂构造是煤层顶板稳定性影响因素中最重要的因素,以兖州煤田鲍店煤矿为例,分析了兖州煤田顶板断裂构造特点,探讨其对煤层顶板稳定性影响,分析了小断裂对煤层顶板的稳定性影响,断裂密集区的煤层顶板最易垮落,特别是交错断裂区更易产生顶板垮落式冒顶. 相似文献
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Sun Zequan Feng Hao Wang Wenhai Guo Tao Wang Qingwei Tang Peng 《Geotechnical and Geological Engineering》2022,40(3):1103-1119
Geotechnical and Geological Engineering - The lithology of the roof of the mining roadway is compound and the thickness of each layer varies considerably, and it is disturbed by dynamic load all... 相似文献
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Two roof pendants in the Hope Valley area, Alpine County, containabundant calc-silicate assemblages which can be related to univariantor invariant equilibria in the CaO-Al3O3-SiO2-H2O-CO2 system.Such assemblages are considered to represent components of reactionsthat buffered the chemistry of the pore fluid. Through dataobtained from microprobe analysis it is concluded that solidsolution in plagioclase, garnet, and clinozoisite are importantvariables such that on a TXco2 projection each sample had aunique path during metamorphism. Differences in the plagioclasecomposition of nearby samples with assemblages related by thereaction: grossularite(s.s)+quartz = anorthite(s.s.)+wollastonite, suggest unique equilibration temperatures for assemblages inlocal domains. In the Twin Lakes pendant in Fresno County, thereaction: clinohumite+calcite+CO2= 4forsterite+dolomite+H2O, is importantin magnesian marbles. Contrasting parageneses, which are relatedby this equilibrium, are considered to reflect variations influid composition. Constrasting assemblages in calc-silicaterocks, which are linked by the reactions: calcite+quartz= wollastonite+CO2, tremolite+calcite= dolomite+diopside+CO2+H2O, exist down to the scale of a thin section. Variation in Ti contentof idocrase may be an important factor in assemblages linkedby reactions involving this phase. This study suggests that during contact metamorphism of calcareousrocks in the Sierra Nevada, H2O and CO2 behaved as ‘initialvalue components’ (Zen, 1963) whose activities were controlledby reactions withion local systems. 相似文献
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Gregory Molinda 《Geotechnical and Geological Engineering》2008,26(5):553-566
NIOSH has recently completed a study of the interaction between polyurethane (PUR) and coal mine roof in order to determine
the mechanism of reinforcement, in both highly fractured rock and unfractured rock. Four case studies of PUR reinforcement
are presented. At a West Virginia site, a borehole camera revealed the location of roof voids and guided the PUR injection.
By injecting polyurethane into a zone from 0.6 to 1.8 m (2–6 ft.) high in the roof, a roof beam was created and ongoing intersection
falls were halted. In another highly fractured roof in a western Pennsylvania mine, a total of 5.8 cm (2.3 in.) of rubbleized
rock was found in a zone up to 3 m (10 ft.) into the roof. Untargeted PUR injection filled approximately 1/2 of the fractures.
These two case studies showed that it is not necessary to fill up 100% of the void space to create stability. In the other
two field sites, polyurethane was injected into weak, but unfractured roof. Post-injection video monitoring showed that weak
bedding planes were hydraulically wedged open and polyurethane injected along bedding. The reinforcement value of this injection
method is limited because of the wafer-thin layer of PUR introduced along bedding, and the lack of a PUR “webbing” which would
serve as a structural framework to provide strength. It was determined that video inspection prior to PUR injection can aid
in identifying the fracture zones to target, and minimize “blind” pumping and loss of PUR. 相似文献
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Li Yang Ren Yuqi Liu Yikun Wang Nan Lei Xinghai 《Geotechnical and Geological Engineering》2022,40(9):4345-4356
Geotechnical and Geological Engineering - In view of the phenomenon that upright triangular zone and inverted triangular zone of the collapsed roof appeared alternately in the gob, a mechanical... 相似文献
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Han Changliang Yang Houqiang Zhang Nong Li Xudong Liu Yitao Liu Wentao Yao Wei 《Geotechnical and Geological Engineering》2022,40(3):1417-1428
Geotechnical and Geological Engineering - Gob-side roadway excavating could not only notably reduce the loss of coal resources and improve the coal recovery rates, but also greatly mitigate the... 相似文献
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Xue Haojie Shen Shibao Lu Haoran Zhao Renbao Li Peishuai Zhao Yawei Jiang Qibin Wang Longjiang Fan Beizhan Qin Tao 《Geotechnical and Geological Engineering》2022,40(4):2117-2125
Geotechnical and Geological Engineering - With the development of coal resource mining at depth, rock burst and other disasters faced by deep mining are more and more common. However, deep mining... 相似文献
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理论分析与实际资料证实,煤层顶、底板反射波的干涉,在煤层厚度所产生的时差小于半个周期时,导致反射波的振幅随着煤层厚度的减小而减弱,且在煤层厚度较小（趋于0m）的情况下,仍然是可以连续对比追踪的;大于半个周期时,反射波的振幅与干涉效应无关。通过实际资料的分析计算发现,在煤层厚度趋于0m时,其顶、底板反射波的干涉所形成的振幅极限值仍然是砂、泥岩界面反射波振幅的3倍,依据这个特征可有效识别煤系地层中的薄、无煤带。 相似文献
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P. P. Nomikos P. V. Yiouta-Mitra A. I. Sofianos 《Rock Mechanics and Rock Engineering》2006,39(2):121-129
Summary. An analytical method is presented for the calculation of the load carrying capacity of two-dimensional asymmetric rock wedges
when the loading on the joint faces is non symmetric, such as the case of an asymmetric wedge formed in the roof of a circular
tunnel in an inclined stress field. The pull out force that causes yield at one of the joint faces is evaluated from formulae
based on the limiting equilibrium conditions assuming a purely frictional joint resistance. Next, the total pull out force
required for the secondary face to yield is calculated. During this step, the wedge is further displaced and while the primary
yielding face is plastically deformed, the other face is still in the elastic range until failure. Validation of the analytical
procedure is obtained with the UDEC code, which provides an implementation of the Distinct Element Method in two dimensions.
When the assumptions made in the analytical procedure are valid, the analytically calculated values for the pull out resistance
of the wedge are computed to be close to the numerically obtained ones. 相似文献
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Creep Failure of Roof Stratum Above Mined-Out Area 总被引：1，自引：0，他引：1
By taking into account the rheological behavior of the rock mass, the creep failure of a roof stratum seated on pillars in mined-out area is analyzed through a newly developed visco-elastic model. The time-dependent deflection of the roof stratum is obtained by numerical inversion of Laplace transform. The study shows that when creep properties of both the pillars and roof stratum are considered, the expected deflection in the roof stratum increases with time. Consequently, the roof would fail when the critical tensile stress is reached as the result of the increased deflection. To demonstrate the present analytical procedure, the failure time of roof stratum of the Xingtai Gypsum Mine in China was estimated, and the results obtained agreed with the observation. The case study indicates that the analytic approach provides a new way to assess the potential impact of the time-dependence of the roof stratum deformation and is useful in predicting its stability above a mined-out area. 相似文献
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结合自然通风的基本原理和国外的一些建筑实例，分析了现代建筑屋顶在建筑各种自然通风系统中的作用，提出了屋顶应采取的相关构造措施，以节约建筑能耗，保护人类身心健康。 相似文献
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Ma Peng Shimada Hideki Sasaoka Takashi Hamanaka Akihiro Dintwe Tumelo K. M. Pan Donjiang 《Geotechnical and Geological Engineering》2021,39(6):4677-4687
In this paper, the behaviour of the pipe roof method with different pipe roofs disposition schemes including the pipe roof gate system and L-shaped system is discussed in terms of ground settlement reduction in the condition of underground space construction adjacent to the existing structure by using numerical simulation method. Considering the construction sequences of parallel underground tunnels with rectangular cross sections, the appropriate parameters and ground response characteristics of the corresponding pipe roof methods are evaluated by the ground surface displacement. The results indicated that the construction impacts from new buildings can be reduced by the pipe roof method. However, the theoretical performance of pipe roofs is highly dependent on the spacing between two structures. Generally, the L-shaped system is more effective in case of the distance (D) that is less than or equal to 1/2 width of box culvert (R) under the condition of a new structure constructed nearby the existing building. When two structures are constructed simultaneously, the excavation and the construction of structures influence each other reciprocally. The conclusions could provide a reference for the pipe roof method with the application scenario of adjacent building protection.
相似文献20.
帷幕注浆在建井时应用于封堵地下水涌入技术已经比较成熟,但用于封堵地层中气体涌入危害仅见个别实例。在总结前人研究成果的基础上,借用水力学安全厚度的计算方法,研究了煤矿巷道开挖碰到含高压瓦斯、H2S气体构造破碎带的情况,首次将管棚支护技术与帷幕注浆法相结合,确保安全掘进的技术措施。并将研究成果应用于四川龙滩煤矿＋450回风石门的掘进,取得了成功。 相似文献