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充填采矿法是现代矿山广为采用的高效无废采矿法,充填钻孔是充填系统的"咽喉"。充填钻孔的使用寿命因素除了输送介质的物理特性、系统的力学特性、管道材料特性外,钻孔偏斜等施工质量成为决定性因素。充填倍线指标是充填钻孔设计的主要依据。充填钻孔施工方法与工序质量控制是保证充填孔质量的关键。在分析了影响充填钻孔使用寿命因素和充填钻孔施工难点的基础上,总结和介绍了充填钻孔的施工方法和质量控制措施。 相似文献
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《Geomechanics and Geoengineering》2013,8(4):269-280
A mathematical model is proposed to simulate isotropic compression test results obtained for specimens of silty sand mixed with different cement contents and cured at different void ratios. The ability of the model to represent the isotropic test results of specimens with different cement contents cured at high and low void ratios under high confining stresses was successfully checked. The physical meanings of the parameters established by the model were also evaluated. Finally, the applicability of the model to other artificially cemented soils was demonstrated. 相似文献
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Centroid depth of earthquakes is essential for seismic hazard mitigation. But, various studies provided different solutions for the centroid depth of the damaging 2013 Lushan earthquake, thus hindering further studies of the earthquake processes. To resolve its centroid depth and assess the uncertainties, we apply the teleseismic cut and paste method to invert for centroid depth with teleseismic body waves in the epicentral distance of 300-90~. We performed the inversion for P waves only as well the case of both P and SH waves and found that both cases lead to depth solutions with difference less than 0.5 km. We also investigated the effects on depth inversion from azimuth gap of seismic stations, source duration, and comer fre- quency of filter. These various tests show that even azi- muthal distribution of seismic stations is helpful for accurate depth inversion. It is also found that estimate of centroid depth is sensitive to source duration. Moreover, the depth is biased to larger values when corner frequency of low-pass filter is very low. The uncertainty in the velocity model can also generate some error in the depth estimation (- 1.0 km).With all the above factors consid- ered, the centroid depth of Lushan earthquake is proposed to be around 12 km, with uncertainty about 2 km. 相似文献
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北京时间2013年1月29日,哈萨克斯坦发生MS6.1地震,为了提高对地震震源机制解的认识,并进一步了解震源区的应力场特征,利用CAP方法反演了此次地震序列震源机制解.反演结果表明,MS6.1地震节面Ⅰ的参数:走向241°,倾角80°,滑动角7°;节面Ⅱ的参数:走向150°,倾角84°,滑动角170°;P轴方位为196°,倾角2°,T轴方位为105°,倾角12°;矩震级MW为6.1;矩心深度为13km;震源类型是左旋走滑型.此次地震序列破裂优势方向为NEE—SWW,倾角以30°~60°居多,滑动角以60°~120°、-60°~-120°居多;P轴方位的优势取向为近NE—SW向,接近水平的居优;T轴优势取向为近SEE—NWW向,接近垂直的居优;震源机制类型以倾向滑动型为主.反演结果与断层的分布、余震分布及哈萨克斯坦中天山(伊犁盆地西部)NEE—SWW向应力场有很好的一致性. 相似文献
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After placement of cemented tailings backfill (CTB), which is a mixture of tailings (man‐made soil), water, and binder, into underground mined‐out voids (stopes), the hydration reaction of the binder converts the capillary water into chemically bound water, which results in the reduction of the water content in the pores of the CTB, thereby causing a reduction in the pore‐water pressure in the CTB (self‐desiccation). Self‐desiccation has a significant impact on the pore‐water pressure and effective stress development in CTB and paramount and practical importance for the stability assessment and design of CTB structures and barricades. However, self‐desiccation in CTB structures is complex because it is a function of the multiphysics or coupled (i.e., thermal, hydraulic, mechanical, and chemical) processes that occur in CTB. To understand the self‐desiccation behavior of CTB, an integrated multiphysics model of self‐desiccation is developed in this study, which fully considers the coupled thermal, hydraulic, mechanical, and chemical processes and the consolidation process in CTB. All model coefficients are determined in measurable parameters. Moreover, the predictive ability of the model is verified with extensive case studies. A series of engineering issues are examined with the validated model to investigate the self‐desiccation process in CTB structures with respect to the changes in the mixture recipe, backfilling, and the surrounding rock and curing conditions. The obtained results provide in‐depth insight into the self‐desiccation behavior of CTB structures. The developed multiphysics model is therefore a potential tool for assessing and predicting self‐desiccation in CTB structures. 相似文献
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离心模型挡土墙试验设备的研制 总被引:1,自引:0,他引:1
土压力问题是土力学和岩土工程领域的基本研究课题。土压力离心模型试验是验证土压力计算方法和研究土压力形成物理机制的有力工具。笔者研制开发的土压力离心模型试验设备,可用于刚性挡墙的静止土压力和平动模式下主动侧土压力的研究。该设备采用电机作为驱动系统,使得挡墙能够缓慢均匀地位移;配备有控制挡墙位移的自动控制系统,使得挡墙在离心加速度增大的过程能够保持静止状态。针对填土面水平、墙后填土为砂土的情况进行了离心模型试验,测量了墙背土压力及填土位移场随挡墙位移量的变化。试验结果规律好,验证了设备的有效性。 相似文献
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复合填料是以废铸砂、粉煤灰、聚苯乙烯颗粒(EPS)、水泥和水为原料,拌合后形成的一种轻质填筑材料。其中,EPS颗粒含量适当时,能减少或消除复合填料的冻胀和融沉,可作为季节性冻土区的路基填料。假设复合填料中除EPS颗粒外的骨料颗粒、孔隙冰为刚性介质,同时考虑EPS颗粒变形和填料孔隙变形对复合填料冻结过程的影响,在已有的冻土水热耦合分离冰模型的基础上,得到考虑EPS颗粒变形影响的饱和填料一维冻结水热耦合控制方程,进而预测填料的冻胀量。与室内模型试验结果对比表明,本文模型可用于该种具有弹性颗粒复合填料的冻胀量模拟,为工程中冻胀量预测提供依据。 相似文献