多组结构面条件下,针对常规的CSMR法修正结构面方位系数时评价结果会产生一定偏差的情况,文中提出采用改进的加权平均法和综合评估法来修正结构面方位系数,以提高 CSMR 法评价结果的准确性.28 个矿山边坡实例的评价结果表明,改进的CSMR法与常规法计算值非常接近,相关性系数很高,但改进方法考虑了几组结构面共同影响边坡稳定的叠加效应,修正后的CSMR 值与RMR 值的相关性较常规方法更高,特别是当CSMR值处于岩体等级边界时,改进方法评价结果可能与常规方法相差一个等级.因此,在工程实践中,采用改进的CSMR法来评价矿山边坡的稳定性,结果更加准确、合理.

预制了含中心圆孔的不同倾角花岗岩裂隙试件,并开展了单轴压缩实验.以典型实验结果为基础,根据细胞自动机分析原理,构建了对应的应变软化模型,采用CASrock软件开展单轴压缩断裂力学特性研究.实验结果表明:数值模拟与实验结果吻合较好,裂隙倾斜方向与轴向应力夹角越小,则试件强度越大;预制裂隙倾角为0.时强度最小,90.时强度最大;在不同裂隙倾角下试件破坏模式有差异,倾角越小,张拉破坏特征越显著;倾角为0.时,圆孔顶端首先张拉起裂,而端部翼裂纹扩展滞后于张拉裂纹;倾角为45.时,张拉裂纹的扩展明显弱于翼裂纹;倾角为90.时,张拉破坏特征可以忽略,试件表现出沿裂纹端部的剪切破坏特征.实验结果验证了岩石抗拉能力弱于抗剪能力的事实,以及细胞自动机分析方法的可靠性,可为裂隙岩体力学性能研究及相关工程应用提供理论支撑.

在山坡露天矿开采过程中,滚石是常见的、不可避免的地质灾害,严重危害矿山开采和人员安全.综合考虑德尔尼铜矿边坡和滚石的实际情况,选择在4336 m水平预留平台的防治方案,平台宽度为10.33 m和20.83 m时边坡安全系数能够达到许用安全系数要求.基于滚石模拟计算方法,应用RocFall软件对滚石的轨迹进行了预测分析,得到了滚落在剖面各个位置的滚石速度、数量和能量,并根据这些指标进行分析比较,获取了滚石防护的有利数据.对比分析后确定平台宽度为20.83 m的方案,采取多种组合防护措施,在平台前沿设置堆土围挡和在滚石能量最小的地方设置柔性钢丝防护网.研究结果为类似矿山的滚石灾害防治和平台预留提供参考.

以刚果(金)卡莫亚铜钴矿1#排土场边坡为研究背景,采用离散元PFC2D数值分析软件建立了排土场边坡模型,并对排土场边坡5个不同剖面进行了稳定性数值模拟研究,得到了排土场边坡在自然状态和含水状态下的颗粒位移变化云图.结果表明,自然状态下,排土场边坡剖面1?1和2?2均为稳定状态;剖面3?3、4?4和5?5稳定性较差,由于岩层关系,边坡容易顺着岩层发生滑坡.含水状态下,5个边坡剖面均为不稳定状态,且边坡强度较小,降水时易发生滑坡灾害.排土场整体破坏的滑面形状为近圆弧型,因此边坡滑动模式为"圆弧型滑动".研究结果可为同类型排土场安全稳定性分析提供参考.

为了得到矿山塌陷坑陡倾斜边坡稳定性情况,采用phase2有限元分析软件分析模拟了边坡稳定性.得到了以下几点结论:(1)边坡岩体的应力大小随深度的增加而增大,越接近坡面主应力值越小;(2)通过二维有限元分析边坡位移较大,有失稳的可能;(3)分析结果显示塌陷区边坡上部凸起部位是目前滑塌产生的主要位置.研究结论可以为矿山塌陷坑治理提供参考.

为了解决某铜矿实际生产过程出现的采剥不协调的问题,开展了露天采场采剥优化与边坡稳定性研究,研究结果表明:在保证前3年出矿量的前提下,第4年开始作为过渡时期,加大剥离量,可改善目前采场欠剥离的现状.优化设计后剥采比有所降低.通过本次采剥优化设计,以及对有效硫的合理利用,均衡了出矿品位,保证了每年采出铜矿石品位维持在0.45％～0.47％.每个边坡的安全系数满足规范要求,边坡处于稳定状态.

为了得到刚果(金)某铜钴矿深部矿体采场最优矿房宽度、地表危险范围与岩层移动角,采用数值模拟软件MIDAS?GTS/NX建立了不同矿房宽度的三维精细化模型,得到了地表位移、矿房应力与塑性区分布,采用数值模拟研究了地表危险范围与岩层移动角.结果表明,依据地表位移、矿房最大主应力、最小主应力和矿房塑性区,判定矿房最优宽度为18 m左右;比较了3种矿房宽度条件下的地表危险范围,以采场宽度18 m开采深部矿体产生的地表移动危险变形较为合理;依据数值分析结果,岩层移动角推荐73°～82°.研究成果可为矿山安全生产提供参考.

针对边坡监测数据的时效性问题,运用叠加马尔科夫链对边坡位移增量进行预测,选取符合马尔科夫链数据要求的位移增量作为预测依据,采用均值-方差法将数据划分为3个状态分级数据区间,并对2019年11月1日至2019年12月30日的60个数据进行分级,得到了不同步长的转移矩阵和均值向量,预测了2019年12月31日、2020年1月1日和2020年1月2日的位移增量分别为2.88、2.84和2.73,预测精度可达到97.3％、89.08％ 和89.75％,预测精度高、效果好,为边坡位移监测数据发挥预警作用提供了案例支撑,对处理矿山边坡监测数据具有参考意义.

Rocks can be used as building materials. In this study, based on the effect of freeze-thaw cycles (FTC) on the properties of water-saturated rocks and the theory of rheology, an elasto-visco-plastic model based on stress functions is proposed, which consists of the elastic, viscoelastic and viscoplastic submodels. The elastic strain shows obvious time dependence and is different from the traditional one in the theory of creep. Although the Kelvin model can be used to fit the relationship between elastic strain and time during the freezing process, but not suitable for thawing process. A threshold element obtained by improving the classical plastic element in rheology is applied to improve the Kelvin model to simulate the viscoelastic behavior of rocks, which only has the action of a valve without any plastic flow and does not work during the thawing process. The viscoelastic strain will be generated after the frost heave stress is greater than σftev, after thawing, it will not recover until time tends to infinity. The viscoplastic strain will be developed when the frost heave stress exceeds σftvp, which can be divided into two substages during the freezing process, namely the substages of stress growth (tvp⩽t⩽tcf) and stress constancy (tcf⩽t⩽tn). The viscoplastic strain will continue to develop until the frost heave stress is reduced to σftvp after thawing. Thus it can be seen that the characteristics of viscoplastic strain show a unique process of damage development of water-saturated rocks during the freeze-thaw (FT) process. Finally, the model is simplified by a piecewise linear function and adopted to fit the strain-time data of water-saturated red sandstone samples during the freezing process.

Based on the similarity theory, a physical testing model with scale of 1:10 was designed and fabricated. The Wenchuan wave (WC-XZ), Darui artificial wave (DR-XZ) and Kobe wave (K-XZ) were adopted as excitation waves which was XZ directions (horizontal and vertical loading at the same time). A series of shaking table tests were carried out to study the effect of the types, directions and peaks acceleration of the seismic waves on the acceleration response laws of the shallow-buried bias tunnels with small distance. The results show that: (1) in the horizontal direction, the types of the seismic waves have a little effect on the acceleration response, but the law is opposite with Kobe wave being the most serious, followed by Darui artificial wave and Wenchuan wave in the vertical direction. (2) The existing slope has a significant effect on the acceleration response of the right hole which is different from that of the left hole. (3) The acceleration response of the tunnel in the vertical direction is more severe than that of the horizontal direction and the acceleration amplification factors in vertical direction are is generally 1.02-3.94 times that of the horizontal direction. (4) in the seismic design of tunnel, different seismic measures should be adopted in different directions. The results have a significant reference for the anti-seismic design of the tunnel.

In order to verify the residual pillars in underground goaf can be mined after filling the underground goaf with filling materials, the three-dimensional refined model is established to simulate the process of mining residual pillars. The residual pillars include interstall pillars (IP) and top pillars (TP). The rock mechanics test and different proportioning tests of filling materials have been carried out. Three schemes for mining residual pillars have been proposed. According to the engineering situation of the mine, the numerical models corresponding to the three schemes are established, such as model1 (M1), model2 (M2), model3 (M3). The MIDAS-GTS/NX software is used to build three-dimensional mine model of different mining scheme. Two criteria were used to determine whether the pillar can be mined, which are the deformation of the strata and the distribution of the plastic zone. Finally, the residual pillars that can be mined are discussed. The results show that some of residual pillar can be mined after filling the goaf with filling body material. The mining of the residual pillar causes the strata deformation and the plastic zone in the rock mass. According to the numerical simulation results, different ore quantity can be mined with different mining schemes. Compared with the other two mining schemes, the scheme 3 (M3) has little effect on the strata deformation and the formation of plastic zone. Moreover, the 8.61 × 108 kg (63% of the total) ore body can be mined with the scheme 3 (M3). The conclusion can be used for reference in similar mine.

In order to study the formation and development mechanism of surface subsidence in Chaganaobao iron-zinc mine, Rongguan mining industry, Inner Mongolia, a detailed engineering geological survey was carried out in the mining area. The occurrence of structural planes of skarn and tuff were statistically analyzed by using software Dips. Based on the investigation results of subsidence pit and underground goaf, the formation and development mechanism of surface subsidence were analyzed in detail. The results show that: (1) there are three and four groups of dominant structural planes of skarn and tuff in the mining area, and the dip angles of structural planes vary from 77 degrees to 81 degrees and from 85 degrees to 90 degrees respectively. (2) The collapse pit forms a steep free face of rock mass on the three sides of the east-west and the south, which is mainly destroyed and collapsed in the form of dumping. Step type landslide is formed in the north side of the collapse pit, which is mainly destroyed in the form of arc-shaped landslide. (3) The formation mechanism of subsidence pit is mainly divided into four stages: natural stability stage - caving formation stage - caving extension stage - surface subsidence stage. The west, south and east sides of the collapse pit consist of three development stages: unloading rebound stage, fracture opening stage and fracture surface collapse stage. The development stages of the north side of the collapse pit include unloading rebound stage, compressive tensile crack bottom-up cracking stage and slip surface through slip stage. (4) A steep slope is formed at the footwall of the ore body, and a large number of fractures with different sizes and widths are generated along the strike of the ore body (NE30 degrees), including some staggered fractures. The formation of surface subsidence is determined by multiple factors, among which the unique geological condition is the internal cause, whereas the underground mining activity acts as the inducement. The internal and external factors together account for the formation and development mechanism of the subsidence pit. (5) Subjected to the active toppling failure and passive traction of the surface soil arc landslide in the north side, the rock and soil masses in the northeast side of the collapse pit have experienced a special form of toppling failure. The findings of this paper provide references for mine safety production and collapse pit treatment.

露天开采境界的圈定是整个露天矿山开采设计的基础.以刚果(金)某铜钴矿露天采场为研究对象,针对这种矿石价值高、品位高,但是服务年限短、开采技术难度大的露天矿山,从安全及经济效益角度出发,提出了基于边坡稳定性分析的"矿体三维模型构建-边坡稳定性研究-资源量估算-境界优化-采矿设计"的露天开采境界优化方法,在确保边坡稳定的基础之上,尽可能多开采矿石,提高矿山开采的经济效益.优化后的新境界将原设计的露天坑底向下延伸了2个台阶(24 m),多采出矿量约181.14×104 t,延长矿山服务年限近2年;同时,提高了整体边坡角,减少了废石剥离量370×104 t.

为了探明刚果(金)卡莫亚铜钴矿南Ⅱ露天采场边坡滑动机理,以弹塑性有限元和强度折减为理论基础,采用有限元专业分析软件Phase2对卡莫亚南Ⅱ露天边坡4个分区的代表性剖面进行了应力、渗流以及爆破振动力的多因素耦合分析.从现场踏勘结果来看,目前南Ⅱ露天采场边坡除了东边坡局部有小型滑坡及北东角1480m平台第四系粘土层边坡开裂外,整体是稳定的.以最终设计境界为基础建立的各分析模型应力分布以压应力为主,坡顶有少量拉应力产生;边坡主要是向采坑临空面移动,坡脚坑底位移向上隆起,以水平位移为主,总位移较大处均位于坡体中部偏向坡脚位置;以剪切破坏为主,破坏区主要分布在坡项及坡脚.边坡的滑动机理为:在地下水和爆破的共同作用下,随着折减系数的增加,边坡坡顶和坡脚的剪切破坏区逐步向坡体内延伸,并在岩体强度低的砂砾岩体内或者砂砾岩和白云岩交界的位置贯通,此时边坡位移发生突变,边坡开始整体滑动;滑动模式为“圆弧滑动”或者“剪切作用下的圆弧-切层组合滑动”.建议矿山在临近终了边坡处采取如预裂爆破等控制爆破技术措施,切实做好边坡的截排水措施.以边坡稳定性研究结论为基础,对南Ⅱ露天采场境界进行了优化调整,将原设计边坡角43°～45°提高到46°～50°,极大地减少了剥离量,取得了良好的经济效益.

为了得到某铁矿采场结构参数和最优开采顺序,采用Bieniawski矿柱强度设计公式对采场结构参数进行了优化.利用数值模拟方法建立了3个不同开采顺序的分析模型,模拟了开采现状和下步开采过程.研究结果表明:设计的"棋盘"方式的矿房、矿柱布置形式,有利于地压控制、通风、矿柱回收和保护地面的建(构)筑物等;各盘区之间在盘区大矿柱的隔离作用下,相互之间的影响较小;最优的开采顺序为由北向南开采,其次为从中间到两边开采;根据矿柱强度设计公式和三维数值模拟分析综合确定了采场结构参数.研究结果可为相似矿山采场结构参数研究提供参考.

The stability of open-pit slope is related to mine safety, especially for high and steep slope. In order to obtain the design slope stability and slope angle optimization of K mine open-pit in Myanmar, limit equilibrium analysis method and three-dimensional numerical simulation are used to carry out the study on the slope stability. The results show that: (1) The safety factor of the designed slope is larger than the allowable safety factor by using the limit equilibrium analysis, which belongs to the stable slope. Some areas can be optimized for design. (2) Through three-dimensional numerical analysis, the design slope and the optimized slope are both stable. The area with large deformation of the optimized slope is mainly concentrated in the area of 562 m level moderately weathered pyroclastic rock in area A and 560 m level moderately weathered rock in area B. The calculation results of three-dimensional numerical simulation are basically consistent with the results of the limit equilibrium analysis. (3) Compared with the designed slope, the potential sliding surface position of the optimized slope is lower. The safety factor is smaller, but larger than the allowable safety factor. The shape of the sliding surface of the whole slope is nearly circular arc. The sliding mode of the slope is circular arc sliding. (4) The reasonable slope angle of different engineering geological divisions of the open-pit slope of K mine is determined. The overall slope angle of area A is ≤ 46°. The overall slope angle of area B is ≤ 44°. The overall slope angle of area C is ≤ 45°. The overall slope angle of area D is ≤ 50°. The research results can provide reference for mine safety production.

为了得到查干敖包铁锌矿塌陷区渐进发展情况,以现场调查为基础,建立含地下采空区、塌陷坑三维数值分析模型,模拟矿体开采情况,得到了塌陷区位移与塑性区分布情况.研究结果表明:塌陷坑东西南三侧形成了陡立的岩体临空面,主要以倾倒形式破坏垮塌,不断向岩体临空面后侧发展;塌陷坑北侧目前已形成了滑坡,主要以弧形滑坡形式向后侧发展;随着地下矿体的开采,塌陷区逐渐扩大,主要发展方向为西及北西向,上盘岩体会逐渐垮塌崩落;以塌陷区现状为基础,当井下矿体开采完毕后,上盘岩体垮塌崩落范围预测为长轴412 m、短轴312 m的椭圆形;现有塌陷区岩体以及上盘岩体均有塑性区分布,现有塌陷坑会进一步垮塌崩落,且发展方向为上盘塑性区分布的方向.通过数值模拟分析得到的塌陷区发展方向与通过现场调查分析的结论一致.研究结果可为塌陷区治理设计提供参考.

为了得到铜山口铜矿露天采场南边坡与西边坡的稳定性,采用RocPlane2.0分析软件对边坡台阶进行了平面破坏稳定性研究.研究结果表明:1)受力在Ⅰ～Ⅵ条件下,边坡的安全系数依次降低;在张裂缝、爆破振动力与地震力影响因素的控制对比下,地震力对边坡稳定性的影响较大.2)南边坡与西边坡台阶高度为12m,坡面角≤75°时,6种受力情况边坡的安全系数均大于许用安全系数,边坡台阶不会发生平面破坏;台阶高度为24 m,坡面角≤75°时,6种受力情况边坡的安全系数均大于许用安全系数,边坡台阶不会发生平面破坏.3)建议在台阶并段开采(24 m)时,其台阶的坡面角为75°.研究结果可为矿山安全生产设计提供参考.

根据刚果(金)排土场边坡实际情况,以软弱夹层厚度与降雨量为变量,进行了两者耦合与边坡安全系数的影响研究,基于Geostudio-SEEP/W、SLOPE/W模块的计算能力,应用Bishop方法计算了在不同夹层厚度、不同降雨量下的边坡最小安全系数,同时进行了排土场边坡的滑动面分析及渗流分析.研究表明:降雨量增加,水位逐渐上升,抗剪强度减弱,安全系数逐渐降低;软弱层厚度增加,滑面半径增大,抗滑力减小,安全系数减小,降低速率大于降雨.

依托刚果金卡莫亚铜钴矿区南Ⅱ露天采场边坡为具体工程实例,运用极限平衡计算方法,研究了该露天采场边坡的稳定性,研究结果表明:在计算方案Ⅰ～Ⅲ与Ⅳ～Ⅵ条件下,边坡安全系数呈现出依次降低的变化规律;A区与C区台阶高度为24 m的情况下,坡面角分别为60°～70°与60°～65°时,6种计算方案下边坡的安全系数均大于许用安全系数,边坡台阶不会发生平面破坏;6种计算方案下边坡的安全系数整体呈现出逐渐降低的趋势,自重(有张裂缝)+地下水+爆破振动力状况对边坡稳定性影响最大,且张裂缝因素起主导作用.研究结果可以为类似工程提供参考.