为解决当前地下空间开发适宜性评价中地上地下指标割裂考虑及指标状态对整体权重影响被忽视的问题,结合熵权和变权思想提出一种改进熵权法三维评价流程.以广东琶洲岛、东莞滨海湾新区和南通重点规划区为实例,构建了符合三者地质特征的惩罚型状态变权函数,基于Petrel建立三维地质模型,采用Kriging法全域模拟,最后从数理统计、整体模型和局部剖面层次对改进熵权法前后结果进行对比分析.结果表明:熵权法可有效将地上地下指标纳入评价体系,改进熵权法相较单一熵权法在保证整体分布准确基础上对局部细节刻画有明显优势;三个研究区评价结果模型与当前城市发展现状吻合度高,验证了改进熵权法先进性、科学性与实用性.

以部分已开通地铁的38个城市为研究样本,分析影响地铁申报的GDP、市区常住人口、一般公共财政预算收入和全年日均客运强度等指标的现状,并分别从横向和纵向角度分析地铁建设指标与7个社会经济指标的相关性.结果表明:部分城市自身的财力和地铁运营能力尚显不足,在地铁建设规模和节奏上应合理把控;不同城市的地铁建设指标与其GDP、一般公共财政预算收入有较强线性相关;以北京为例的研究发现,同一城市不同时期的地铁建设指标与其GDP、人均GDP、市区常住人口、一般公共财政预算收入和人均预算收入等指标高度线性正相关,而与通勤高峰拥堵指数线性负相关.建立的多元线性回归模型反映出经济和人口是北京近10年地铁建设的主要驱动力.该研究可为以后各城市根据自身社会经济水平合理控制地铁建设的申报进度以及促进城市轨道交通有序发展提供参考.

近年来,由于矿山资源枯竭以及国家供给侧改革政策的实施,大量矿山面临关停,倘若只是简单关闭则会造成大量资源浪费,同时引发相关地质灾害问题.同时,关停的矿山仍然遗留了大量的资源可供利用,矿山地下空间作为一类特殊的地下空间资源,具有隔音隔震、恒温恒湿、屏蔽性好等天然优势,近来逐渐被越来越多的学者以及相关部门重视.本文以金属非金属矿山地下空间为研究对象,系统梳理我国金属非金属矿山地下空间资源分布规律及利用现状,并提出相应开发利用对策.以梅山铁矿为典型案例,结合当前国际废弃矿山成功开发利用模式及案例,提出地下储库型、污水处置型和科教型三种开发利用模式.本研究成果可以为我国金属非金属矿山地下空间利用决策提供战略支撑,为国家合理布局金属非金属矿山地下空间开发利用模式提供理论参考.

An improved thermal response test method called the stratified thermal response test (STRT) was proposed and a corresponding system was developed in this study. The difference between the STRT and other methods is that the temperature was measured by sensors placed inside the borehole heat exchangers (BHEs) at different depths to obtain the virtual thermal conductivity in each stratum. The method was validated based on the measurements and determination of the thermal conductivities for two different sedimentary geological conditions using three approaches and was applied to determine the key heat transfer layer and the optimum buried depth of the vertical BHEs. The discrepancies between the thermal conductivities obtained by STRT and the conventional thermal response test were 2.5% and 2.7% respectively, which validates the reliability of the STRT. The positions of the key heat transfer layers of the two boreholes were 50-60 m and 60-80 m respectively; the location of the key heat transfer layer was affected by the intense groundwater activities. At the optimum buried depths of 80 m and 90 m for the two boreholes, the highest heat transfer rate per meter was obtained at the minimum cost. It is expected that the proposed STRT method and system will become increasingly useful for optimizing the depths of BHEs installed in heterogeneous strata because the installation cost can be minimized. (C) 2020 Elsevier B.V. All rights reserved.