邯郸采空区重磁勘探设计

邯长线采空区勘察高精度重磁力勘探施工设计邯长线采空区勘察高精度重磁力勘探施工设计甲方单位：乙方单位：编写人：审核人：技术负责人：行政负责人：二○○九年四月目录1地理、地质、地球物理概况及勘探部署····················12野外采集方法和技术要求··························32.1重力工作方法和技术要求························································································32.2磁力工作方法和技术要求························································································62.3测量工作方法及技术要求·······················································································102.4物性工作方法与技术要求·······················································································122.5资料的检查和验收································································································152.6执行的技术规程···································································································163资料处理解释技术····························173.1研究思路············································································································173.2重磁资料处理······································································································173.3提交的成果·········································································································194队伍组织与工作安排···························204.1队伍组织············································································································204.2施工装备············································································································204.3生产进度安排······································································································215生产管理措施······························215.1质量管理措施······································································································215.2HSE管理············································································································216费用预算································2811地理、地质、地球物理概况及勘探部署测区位于河北省武安市磁山～阳邑之间，属太行山东缘，地形较平缓，为磁铁矿区。该地采矿、冶铁历史悠久，现多为私企开采。地层由上而下基本为第四系黄土、石灰岩及闪长岩，铁矿成矿于闪长岩侵入石灰岩接触带上，一般呈立体团状分布。磁山地区开采深度较浅，可见露天开采痕迹，阳邑地区约180m以下。地表多见因采空引起的塌陷坑，大小深度不一，邯长线在阳邑一段因此而改线。铁矿被开采后，该段地层变为空气或松散充填物，其密度层缺失，在地面重力和磁力上会产生异常，如图1-1模拟所示：图1-1重力模型正演结果该采空模型顶深100m，岩洞高2m，长10m，正演计算可以引起20微伽重力异常，因此采用高精度重力勘探开展工作有较好的地球物理前提，考虑到重磁同源效应及铁矿的高磁性，铁矿采空后地表磁场会出现变化，因此采用重力、磁法联合解决该区的采空问题是一种较好的手段。根据该区概况及勘探任务的要求，本次勘探部署重、磁力勘探面积为2×0.5km2，考虑到重力边界效应，地形测量数据应在扩展到测区外围2km远。由于探测目标小，本次重磁力勘探测区测网按20米×20米方式布设；在异常区，如果不能确定边界，需加密至10m×10m，测线方位角与原物探测线平行。全区初步布设重磁力测线95条，测点2388个，具体见图1-2。2测区范围及角点坐标见表1-1。重磁力勘探工区拐点坐标表1-1拐点Y坐标X坐标A4067660.862019493928.6748B4067660.862019496315.1832C4066449.156519496315.1832D4066449.156519493928.6748东方公司综合物化探事业部于4月1日与委托方进行了接洽和情况了解，在收集资料的基础上编写了本设计书。本设计书以合同规定的地质任务、各项技术指标及各项行业标准为依据，针对测区的实际情况，拟定了完成本次勘探任务的施工方法、预期达到的各项技术指标，以及完成该任务所需的人员设备、预期完成的工期等。本设计经审批后，作为野外生产的依据，对野外生产过程中出现的新问题及设计中未涉及的内容，均以规范为准。如遇有特殊情况，需对本设计做出变更的，须报请甲方批准同意后，方可在野外实施。图1-2测区重磁力勘探部署图32野外采集方法和技术要求2.1重力工作方法和技术要求2.1.1重力仪器试验开工前所有重力仪器必须进行全面检查、调节，并进行下列试验，各项指标达到要求后方可施工。2.1.1.1静态试验静态试验在无干扰的室内进行，重力仪始终处于开摆状态。每30min读取一次读数，连续观测不少于24h，并绘出仪器读数随时间的变化曲线，分析仪器的静态性能。其静态掉格曲线应保持线性，平均每小时静态掉格应不大于±0.0042510sm。2.1.1.2动态试验在工区内选取一段路线，要求试验点间的重力段差一般在2.02510sm以上，每台仪器的试验次数不少于2次，每次不少于8h，选择8~10个点采用重复观测法进行。根据试验结果分析仪器的动态性能，动态观测精度不低于±0.042510sm。2.1.1.3一致性试验投入施工的所有仪器，均要进行一致性对比。试验次数不少于2次，试验点数8~10个，要求两点之间重力差较大，点距与实际工作点距相当。如果动态混合掉格试验满足上述要求，也可以利用其试验结果来计算仪器的一致性，仪器一致性精度不低于±0.042510sm。上述仪器试验必须满足设计要求，对于超出设计要求的仪器要认真分析原因，对于不能满足设计要求的仪器不能投入生产，直到稳定后重新试验能满足设计要求为止，必要时应进行调换。重力仪每月测定一次水泡位置和光线灵敏度，超出要求必须调校，并做好记录。施工结束后，重力仪要在同一试验场上进行一次动态和一致性试验，以检验施工期间的仪器性能。2.1.2重力普点观测和精度要求测线采用直线布设，重力点要设立明显的标志，确保检查观测时能够找到测点。普点采用单次观测法施测(如图2-1所示)，每个工作单元首尾连接基点。当天闭合重力基点。早基点连接采用“基—辅—基”方式连接，基点、普通点和检查点均采用两次读数，并且符合规程要求。每个重力工作单元零点位移不大于±0.1202510sm。4图2-1重力基点控制下的普点观测方式示意图点位尽量避开田埂或河堤陡坎，减少微地形的影响。检查点应尽量做到在时间和空间上分布均匀，检查观测尽量执行同一点位、不同工作单元、不同仪器、不同操作员的要求，检查率不少于5%，检查点最大直接差不大于0.1002510sm。重力野外记录要认真，字迹清晰工整，注记齐全；严格按照统一格式填写；不得涂改、擦改、就字改字或连环划改，正常划改应备注，并保持页面清洁和页数完整；各项观测数据和备注要现场填写，保证真实、准确、不得追记或转抄。2.1.3地形改正由于工区地形相对较平坦，对周围地形起伏不超过10°的测点，地形影响可忽略不计，对周围地形起伏超过10°的测点进行近区地改。方法是用森林罗盘和测绳，顺时针方向进行八方位实测，记录相对高差。正东、南、西、北方向水平距离要求20m，对角线方向要求28.28m（如图2-2所示）。重力地形校正，采用实测及1:2000地形图数字化的高程数据。2.1.4重力资料整理2.1.4.1固体潮校正固体潮校正采用下式计算：)()(),(''ftGtGT4223)(00137.0)cos31()(05506.0)(mmmmmRCFZRCFtG)cos31()(02536.0)cos5cos3(332sssmmZRCFZZ20mNNWWSSEE28.28m20mNNWWSSEE28.28m图2-2近区地改示意图52cos00167.0998327.0)(F'4'2'sin00159.0sin01573.000483.0)(f式中：GT(t,′)——固体潮理论值，2510sm；Cm、Cs——分别为月心和日心至地心平均距离，km；Rm、Rs——分别为月心和日心至地心距离，km；Zm、Zs——分别为月亮和太阳对测点的地心天顶距，（°）；δ——潮汐因子，采用平均值1.16；，′——测点纬度和地心纬度，（°）。2.1.4.2零点位移改正系数由下式计算：ttKgg式中：K为零点位移校正系数，min/1025sm；g为普通观测时，终止基点与起始基点重力差，2510sm；g为终止基点与起始基点已知重力差，2510sm；tt，分别为起始基点与终止基点上观测时间，min。2.1.4.3布格改正布格改正采用下式计算：Hgb)0419.03086.0(式中：gb——布格改正值（2510sm）；H——测点海拔高程（m）；——中间层密度，取2.00g/cm3。使用加长脚架时采用下式改正：3086.00419.0)0419.03086.0(10HHgbH1式中：gb——布格改正值（2510sm）；H——测点海拔高程（m）；H1——重力仪底盘至测点（水底）高差（m）；——中间层密度；0——水的密度（1.00g/cm3）。62.1.4.4近区地形改正计算方法采用方域地改：20m的方形近区，根据八方位实测的相对高差用下式计算8个斜顶面三角棱柱体的地校值，然后相加：ABCBBCABBCBDGgti22ln121ln式中：12