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×××××××××××××有限责任公司×××尾矿堆积坝稳定性评价岩土工程勘察报告×××××××××××有限公司2007年7月1日目录文字部分1前言······················································································11.1工程概况·········································································11.2勘察技术要求···································································11.3勘察工作执行的主要技术标准··············································21.4勘察方法及完成工作量·······················································21.4.1工程地质测绘·································································21.4.2钻探·············································································21.4.3取土试样·······································································21.4.4原位测试·······································································21.5有关说明··········································································32场地工程地质条件····································································42.1地形及地貌······································································42.2区域地层·········································································42.3区域地质构造···································································43堆场工程地质条件····································································53.1堆场形态·········································································53.2堆积方式·········································································53.3堆场地层·········································································53.4不良地质作用···································································54拦洪坝场地工程地质条件····························································65物理力学性质指标····································································65.1尾矿土的物理力学性质指标·················································65.2尾矿土的抗剪强度指标·······················································65.3标准贯入试验锤击数··························································75.4重型动力触探试验代表值····················································75.5渗透性············································································76场地水、土对建材腐蚀性评价·····················································87场地地震效应··········································································87.1尾矿坝分级及场地分类·······················································87.2地震动参数······································································87.3地震液化和震陷································································88堆场坝体稳定性分析与计算························································88.1尾矿坝现状分析································································98.2尾矿坝渗流分析································································98.3尾矿坝稳定性评价·····························································98.4尾矿坝加高排渗措施························································129结论及建议···········································································13附件：岩土工程勘察任务委托书图表部分序号图表名称张数附录№1勘探点主要数据一览表112工程地质平面图123工程地质剖面图33-1～3-34土工试验成果报告34-1～4-35单环注水试验成果35-1～5-36水质分析报告26-1～6-27土易溶盐含量分析报告27-1～7-28渗流分析计算图38-1～8-39稳定性计算图98-4～8-181前言*************有限责任公司***尾矿堆积坝稳定性评价岩土工程勘察工作，是根据该公司提出的岩土工程勘察任务委托书技术要求，并受*********有限责任公司委托，由我院于2007年6月完成。1.1工程概况***银花钒矿位于***省***县银花镇梅子沟村，尾矿库位于梅子沟西侧的***，处于糜子沟主沟道。原***坝80年代修建，现无设计资料，该坝原为水库。根据现场踏勘及甲方提供资料知，***初期坝为重力砌石夹心不透水坝，坝高约22.0m，坝底宽约23.0m，坝顶宽3.0m。坝顶轴线长62.0m，坝顶高程598.0m，坝下脚线高程为576.3m，库容约12万m3。该矿从1998年开始向库内排放尾矿渣，采取坝后任意排放。目前库内尾矿渣堆放高程595.51～598.62m，距坝顶平均高程约1.3m，整体呈坝前低，坝后高。该坝于2006年停用，并进行了闭库设计。目前新的尾矿库正在筹备修建之中，为保证矿山正常生产经营，拟将该库做为临时过渡尾矿库，据设计初步估算，坝体拟加高3～10m。该尾矿库排洪系统采用排洪涵洞，排洪涵洞建设在西侧，防洪标准为100年一遇。加高3～8.0m时，按《尾矿库安全技术规程》（AQ2006-2005）第4.1条划分，加高后的尾矿库为五等库。加高＞8m时，按《尾矿库安全技术规程》（AQ2006-2005）第4.1条划分，加高后的尾矿库为四等库。1.2勘察技术要求1）查明尾矿库存在的不良地质作用，评价不良地质作用对堆场的影响，提出合理的防治措施；２）查明尾矿库的地层、岩性，提供尾矿土常规物理力学指标、颗分、渗透系数及抗剪强度指标（C、Φ值）；３）查明目前标高下尾矿库地下水位（浸润线）及变化规律；４）提供尾矿库所在区域的地震烈度及地震动参数，评价堆场的地震效应；5）分析评价已运行坝体的稳定性，继续加高坝体的适宜性和稳定性。6）对尾矿库使用提出合理的工程措施或建议。1.3勘察工作执行的主要技术标准1）《岩土工程勘察规范》（GB50021-2001）；2）《尾矿库安全技术规程》（AQ2006-2005）；3）《岩土工程勘察技术规范》（YS5202-2004）；4）《构筑物抗震设计规范》（GB50191-93）；5）《土工试验方法标准》（GB/T50123-1999）；6）《中国地震动参数区划图》（GB18306-2001）；7）《碾压式土石坝设计规范》（SL274-2001）。报告书中引用上述标准时均以其编号简称。1.4勘察方法及完成工作量本次勘察采用工程地质测绘、钻探、原位测试和室内土工试验相结合的方法进行。1.4.1工程地质测绘在收集场地已有资料的基础上，通过实地调查，查明场地地形地貌、地质界线，查明库区、坝体及其附近有无影响其稳定性的不良地质作用，重点对坝体的稳定状况进行调查。测绘精度1:1000，成图精度1:1000，采用仪器法及半仪器法进行，其成果反映在工程地质平面图上（见附录№2）。1.4.2钻探垂直于坝轴线布置勘探线3条，每条勘探线上布置不少于4个勘探点，共布置13个勘探点。勘探点间距30～50m，钻探的目的是查明尾矿的沉积规律、胶结程度及其物理力学性质指标，查明坝体内浸润线位置，采取土试样和进行原位测试，获得堆场稳定性分析剖面。钻探施工采用两台XY-1型钻机，采用套管护壁钻进，开孔直径130mm，终孔直径110mm。共完成钻孔7个，孔深10～20m。1.4.3取土试样为取得尾矿土的物理力学性质指标，在6个钻孔中进行了岩土取样，共采取不扰动试样11件，扰动试样44件，取样间距为1.5~2.0m。不扰动试样采用薄壁取土器静力压入法或重锤轻击法采取，土样质量为Ⅰ～Ⅱ级。1.4.4原位测试1）标准贯入试验为评价尾矿砂的密实度，对尾矿进行分层，在所有勘探点均进行了标准贯入试验。标贯间距1.5~2.0m。标准贯入试验次数16次。2）圆锥动力触探试验在碎石土中进行了重型圆锥动力触探试验，锤重63.5kg，落距76cm，探头直径74mm，锥角60○，用球式自动抓脱钩装置。3）现场试验为查明废渣的渗透系数，进行现场注水试验。为查明废渣的物理力学参数，现场进行天然重度试验和天然休止角试验。4)室内土工试验和水质分析本次勘察室内土工试验项目为常规土分析（含水量、孔隙比、密度等），此外还进行了直剪、颗分等特殊性试验。为评价堆场水、土对建筑材料的腐蚀性，进行了堆场土的腐蚀性和水质分析试验。土工试验和水质分析执行《土工试验方法标准》（GB/T50123-1999）规程。完成的勘察工作量汇总于表1.4。1.5有关说明1）勘探点位置，是根据甲方提供的1：500《封库平面布置图》中已有建筑物的相对位置，用钢