V B6．0在地下管线数据处理中的应用

介绍了利用VB6．0开发地下管线数据处理程序的关键技术及设计综合表的思路,实现了地下管线普查表格的自动生成,使得工作效率得到提高。     

Biogeochemistry of dissolved carbon,major, and trace elements during spring flood periods on the Ob River

Detailed knowledge of the flood period of Arctic rivers remains one of the few factors impeding rigorous prediction of the effect of climate change on carbon and related element fluxes from the land to the Arctic Ocean. In order to test the temporal and spatial variability of element concentration in the Ob River (western Siberia) water during flood period and to quantify the contribution of spring flood period to the annual element export, we sampled the main channel year round in 2014–2017 for dissolved C, major, and trace element concentrations. We revealed high stability (approximately ≤10% relative variation) of dissolved C, major, and trace element concentrations in the Ob River during spring flood period over a 1‐km section of the river channel and over 3 days continuous monitoring (3‐hr frequency). We identified two groups of elements with contrasting relationship to discharge: (a) DIC and soluble elements (Cl, SO₄, Li, B, Na, Mg, Ca, P, V, Cr, Mn, As, Rb, Sr, Mo, Ba, W, and U) negatively correlated (p < 0.05) with discharge and exhibited minimal concentrations during spring flood and autumn high flow and (b) DOC and particle‐reactive elements (Al, Fe, Ti, Y, Zr, Nb, Cs, REEs, Hf, Tl, Pb, and Th), some nutrients (K), and metalloids (Ge, Sb, and Te), positively correlated (p < 0.05) with discharge and showed the highest concentrations during spring flood. We attribute the decreased concentration of soluble elements with discharge to dilution by groundwater feeding and increased concentration of DOC and particle‐reactive metals with discharge to leaching from surface soil, plant litter, and suspended particles. Overall, the present study provides first‐order assessment of fluxes of major and trace elements in the middle course of the Ob River, reveals their high temporal and spatial stability, and characterizes the mechanism of river water chemical composition acquisition.     

GIS在处置地下管线突发事件中的应用研究——以苏州市地下综合管网应急处置系统为例

随着经济社会的不断发展,城市建设步伐不断加快。近几年,各类地下管线突发事件频发。通过"苏州市地下综合管网应急处置系统"项目的开发和实践,本文试图从总体上论述地下综合管网突发事件的处置过程、应用原理及相关的技术实现,重点阐述了基于"12345"便民服务中心工作平台,在充分利用GIS的网络分析技术的基础上,实现城市地下管网突发事件应急处置的自动化和信息化。     

地下开挖可视化决策的关键技术研究

地下工程开挖导致地层沉陷,这种地质环境效应对该范围内的建（构）筑物、管线、道路、桥梁、水体、农用设施等都可能构成不同程度的损害。为了确保地下工程开挖对地面环境损害最小,提出了利用GIS技术进行地下工程开挖决策设计的思路,并探讨了其可行性与必要性,研究了实现地下工程开挖可视化决策系统的数据处理以及实现可视化的关键技术,建立了数据库E-R模型。     

迭代增量法分析地下连续墙的受力性状

围护结构的位移是影响土压力的重要因素,目前深基坑中地下连续墙分析时采用的增量法没有考虑墙体位移对增量荷载的影响。根据墙体位移对增量荷载的影响,假设在每一步开挖过程中围护墙体位移不变,由此确定初始增量荷载。根据计算得到的位移,用迭代法对增量荷载进行修正,分析地下连续墙的变形和内力。最后,通过与实测资料的对比,证实了迭代增量法的合理性。     

黑河上游水系发育特征分析

对黑河上游山区部分的水系发育特征进行了分析。在1:250 000比例尺的地形图上,黑河河道可以划分为五级。根据Horton的地貌关系统计结果,黑河水系特征不都服从于Horton的河道定律。河道数量定律适用于本地区,但河道分岔比较高。河道长度定律不适用于本地区,在半对数纸上,平均河道长度的累计值与河道级序有较好的直线关系,而河道总长度与级序则呈双对数直线关系。河道频率及河网密度与河谷局地气候呈正相关,湿润气候条件下,河道频率与河网密度较大;反之,干旱气候条件下,河道频率与河网密度较小。但河流的产流则与区域降水量有关。河川径流的泥沙含量与河流切割程度呈正相关,祁连山北坡河流的泥沙主要来源于横向深切河谷。     

Water quality impacts from mining in the Black Hills,South Dakota,USA

The focus of this research was to determine if abandoned mines constitute a major environmental hazard in the Black Hills. Many abandoned gold mines in the Black Hills contribute acid and heavy metals to streams. In some areas of sulfide mineralization local impacts are severe, but in most areas the impacts are small because most ore deposits consist of small quartz veins with few sulfides. Pegmatite mines appear to have negligible effects on water due to the insoluble nature of pegmatite minerals. Uranium mines in the southern Black Hills contribute some radioactivity to surface water, but the impact is limited because of the dry climate and lack of runoff in that area.     

软土地下工程抗震数值模拟的若干关键问题

针对我国地下工程建设项目抗震安全性能设计和评估的需求,并基于目前缺少完善的地下结构抗震分析方法和专门的地下结构抗震设计规范的现状,重点阐述了采用有限元方法进行地下工程数值模拟和分析时需要特别关注的三方面问题：计算范围、土一结构动力相互作用和边界条件。着重分析了有限元网格的划分、土一结非线性接触问题和不同边界条件的适用性,以及这些建模条件对计算结果可靠性的影响。对基于数值手段开展地下工程抗震安全性能的计算、分析和评价,制定地下结构抗震设计规范或规程,可提供有益参考。     

湖北宜昌市暴雨雨型的演变特征

基于1980—2018年武汉国家基本气象观测站逐分钟降雨数据,分别利用同频率分析法和Huff雨型分析法确定武汉主城区历时1 440 min设计暴雨雨型,并采用InfoWorks ICM水力模型软件对雨水管网进行模拟计算,分析两种设计暴雨雨型的雨峰、降雨量时间分布和积水情况,研究结果表明：（1）基于同频率分析法和Huff雨型分析法确定的武汉主城区历时1 440 min设计暴雨雨型均为单峰型,两者雨峰位置均略微超前整场降雨过程的前2/3分位,在降雨时程的60%~70%阶段,前者降雨强度迅速增加,大于后者。（2）在同频率分析法确定的武汉主城区历时1 440 min设计暴雨雨型下,武汉汉口中心城区的淹没面积均大于Huff雨型分析法的确定结果,且水深、流量、流速等峰值均较大。（3）同频率分析法确定的设计暴雨雨型结果使得武汉主城区系统内达标管网比例更低,积水情况更严重。

     

广西忻城福六浪洼地堵洞成库施工实践

为解决广西忻城县城关镇弄长村一带万余人饮水问题及该岩溶石山区干旱农田引水灌溉问题,在广西忻城县隆光地下河福六浪洼地3号天窗下游钻取了投料孔和帷幕灌浆孔,先在投料孔投放碎石骨料,后在帷幕灌浆孔内灌入水泥砂浆或水泥浆液对先期投放的碎石骨料进行固结,修筑地下堵体防渗帷幕对流经福六浪洼地的隆光地下河管道实施堵截,成功地截住了隆光地下河水向下游排泄量,减少了洼地积水通过天窗、落水洞向下游的渗漏量,增加了天窗向洼地的溢洪量,建成了库容约250万m3的溶洼水库,基本解决了城关镇弄长村一带万余人生活饮水难的问题,提高了该溶洼水库周边、岩溶大石山区干旱农田灌溉水平和改善了当地村民的饮水条件。