A Study Transient on Predictive Calculation Method of on Underground Ventilation Network

The authors developed a computer program of transient predictive calculation method on underground ventilation network. The program approximated a field data set of seasonal cyclic changes of air Temperature and humidity at the inlet to the sine curves, and included sensible heat conduction from rock to air current. The temperature of rock around and airway was calculated by finite difference method. The prediction method can be used to calculate the variation of flow rates, temperatures and humidities of air flow in the airways along underground network.     

Experimental Analysis of Vibration Behavior for Large-span Underground Structure

In this paper, a shaking table test for large-span underground structure is introduced. Based on the test, the frequency of inherent vibration, damping ratio and the dynamic response of the structure are studied. The response of the underground structure for vertical seismic excitation is studied as a key point. With the different imbedding depth, the influence of interaction of soil and structure on the earthquake-resistant capacity of the underground structure is discussed.     

ANALYTICAL SOLUTION OF RING SHELL LINING WITH ANNULARLY VERTICAL WALLS MADE CONTACT WITH SURROUNDING ROCK

In this paper,the ring shell lining with annularly verticalwalls made contact with the surrounding rock is considered as a combinationstructure formed of ring shell,inner and outer annular barrels on elastic fo-undation.The complex equation and its solutions of ring shell under deadload of lining and vertical and horizontal surrounding rock pressures are de-rived by the method of complex function.The governing equation and itssolution of the barrels on elastic foundation are also derived by theory ofcylindrical shell.And then,the ring shell lining is assembled by the subst-ructures by means of compatibility conditions of internal forces and defor-mations between them.In the paper,all formulas for the practical computa-tion in engineering are derived,the numerical examples are given and theeffects of the parameters of the lining on the work behaviours of lining alsoare discussed preliminarily     

温室地下蓄热系统换热特性研究

针对现行温室地下埋管式换热系统结构的缺点，为充分利用地下蓄热，提高地温和夜间环境温度，设计了一种新型温室地下蓄热系统。测定了系统蓄热与放热时进出口空气温度、湿度与换热管道出口处空气的流速。试验结果表明，温室地下蓄热系统蓄热和放热时进口空气与出口空气的温度差、焓差较大，其差值随系统运行时间降低，白天蓄热量与夜间释放热量大于系统消耗的电能，蓄热时运行时间不宜大于4.5 h。     

三峡库区紫色土坡地土壤粗骨沙化和酸化特征

土壤侵蚀是三峡库区紫色土坡地土壤退化的主因,并由此造成土壤粗骨沙化和酸化。利用土地特性系列比较法,通过野外调查和室内分析相结合,研究了三峡库区紫色土坡地土壤退化特征,结果表明:(1)与未退化样地相比,不同利用方式和不同坡度段土壤粗化现象明显,表明它们存在不同程度的侵蚀退化。各土地利用类型pH值均有所减少,表征该研究区紫色土向酸性方向发展,特别是园地和菜地。(2)不同利用方式下土壤沙化程度由高到低的顺序是:荒地>建设用地>耕地>草地>林地>菜地>园地。(3)不同坡度段紫色土坡地土壤沙化程度基本随坡度的增加而增大,但>30°坡度段土壤沙化最轻。(4)不同利用方式和不同坡度段土壤粘粒、有机质、全N、碱解氮、全P、速效P、全K、速效K、阳离子交换量、pH值及微量元素之间存在着明显的相关性。     

基于湖泊(水库)沉积物分析的土壤侵蚀研究

土壤侵蚀作为全球性的环境问题之一,受自然和人为因素的共同影响。而湖泊(水库)沉积物作为流域物质迁移的“汇”,可以连续、高分辨率地记录流域土壤侵蚀的信息。通过湖泊沉积指标的研究,可以反演流域土壤侵蚀过程、演化规律。与流域人类活动、气候变化等自然因素综合分析,可对流域土壤侵蚀发生机制等做出科学论断,为目前水土流失治理等提供参考依据。介绍了基于湖泊(水库)沉积物的放射性同位素示踪研究、矿物与磁性分析、粒度分析、孢粉、元素地球化学分析方法应用于土壤侵蚀的研究进展,并对其应用前景做了瞻望。     

水库消落带应算作破坏水土保持设施面积

水库蓄水长时间淹没和浸泡,致使水库消落带的植被几乎全部死亡,坡面土壤流失贻尽,岩石滑塌甚至造成山体不稳,引发滑坡等侵蚀。水库消落带不仅仅应算做水库建设的扰动面积,而且应算做破坏水土保持设施的面积,尤其在我国植被生长良好的南方地区。水库消落带破坏水土保持设施面积应该是正常蓄水位以下水库面积与未建水库前水面面积之差,面积大小可以采用面积量算法和简单估算法得到。     

烟台市中西部及邻区水库淤积研究

将水库淤积按沉积动力学特征分为河流沉积动力淤积和水库沉积动力淤积2种类型,建立了2种淤积类型的动力模型.水库淤积量的大小按水库因水位下降所出露的淤积物面积进行评估.结合陆地卫星TM图像,对研究区内的30个水库,按淤积程度离差分为3级Ⅰ级,DEPDEV＜-0.3;Ⅱ级,DEPDEV=-0.3～1;Ⅲ级,DEPDEV＞1.对比图像平面数据与实测的水库淤积量数据,发现图像数据与兴利库容以下实测数据协同性好.     

基于地理信息系统的土地利用变化制图方法研究

论述了土地利用变化图绘制的一般过程。图例的设计和不同时期土地利用现状图的代数叠加运算是整个编制过程的关键。做图过程中应本着简单实用、形象达意和美观大方的原则进行。分别选取黄河小浪底水利枢纽库周1993和2000年TM遥感影像进行土地利用变化分析,编制出了建库前后的土地利用变化图,计算出了土地覆被变化的转移矩阵并对土地利用变化的结果进行分析。     

Impact of land-use changes and sedimentation on the Muhammad Nur Reservoir, South Kalimantan, Indonesia

The Muhammad Nur Reservoir (MNR) is a major multipurpose reservoir located on the Riam Kanan River in the Indonesian Province of South Kalimantan. The MNR has a high sediment trap efficiency and there is concern that accelerated erosion in the catchment, resulting from inappropriate land use, poses a significant threat to the storage capacity and effective life span of the reservoir. Furthermore, on-going deforestation of large parts of the catchment may have changed the inflow pattern to the reservoir. This paper uses data from fieldwork and published information from different sources to examine the extent of erosion and sedimentation in the catchment and the sediment delivery to the reservoir. Water level variations in the reservoir over a 22-year period are examined for changes that might indicate an alteration of the hydrologic balance in the catchment.