枣庄市十里泉电厂第三水源地地下水位年变幅灰色预测

该文依据往年地下水位监测数据,通过灰色系统理论的预测模型,对枣庄十里泉电厂地下水位年变幅做出预测,分析了岩溶塌陷发展趋势,为由水动力因素引起的岩溶塌陷地质灾害提供防治依据。     

真空预压法在珠江流域某冲填土场地的应用

依托珠江流域某冲填土场地工程实例,介绍了真空预压法的施工参数及应用效果,另对“薄弱部位”泥浆搅拌桩密封墙处地层的强度进行了定量分析,结果表明真空预压法适用于此类场地,加固效果明显,但密封墙位置强度降幅较大,需采取换填等措施二次处理后才能使用,可为其他类似工程提供参考经验.     

青海玉龙滩地区托赖岩群中—早二叠世基性岩墙的发现及地质意义

在玉龙滩地区古元古代托赖岩群变质岩中发现了一套基性岩脉侵入体,岩石类型主要为辉长岩、辉绿岩,侵入于托赖岩群片麻岩、片岩,岩脉长轴走向大多以北西向为主,个别近南北向或北东向,露头规模一般长10~35m,宽5~10m。通过同位素测年分析辉绿岩脉地质时代为早二叠世,结合对地质特征、岩石学特征、岩石化学、地球化学特征的研究,认为其属于拉斑玄武系列,形成于伸展性构造环境。结合本区区域地质分析,该岩脉可能为祁连山造山带加里东期造山运动结束之后,由于陆壳加厚而发生伸展崩塌,造成幔源基性岩浆底侵,形成了该类相当于基性岩墙的产物。反映北祁连地区在早二叠世有一期陆壳加厚伸展背景下的基性岩浆底侵事件。     

Pseudo-dynamic methods for seismic passive earth pressure behind a cantilever retaining wall with inclined backfill

The designing of retaining walls requires the complete knowledge of earth pressure distribution. Under earthquake conditions the design needs special attention to reduce the devastating effect, but under seismic conditions, the available literature mostly uses the pseudo-static analytical solution as an approximate to the real dynamic nature of the complex problem. This paper shows a detailed study on the seismic passive earth thrust behind a cantilever retaining wall with inclined backfill surface by pseudo-dynamic analysis. A planar failure surface has been considered. The effect of variation of parameters such as soil friction angle, wall friction angle and back fill inclination have been explored. A complete analysis shows that the time dependent non-linear behaviour of the pressure distribution obtained in the present method results in more realistic design values of earth pressures under earthquake conditions. Results are provided in tabular and graphical non-dimensional form and compared thoroughly with the existing values in the literature.     

Slip line theory applied to a retaining wall–unsaturated soil interaction problem

An extension of slip line theory to unsaturated soils is presented and applied to the problem of a rigid retaining wall rotating about its toe into unsaturated soils. Suction is introduced using the effective stress concept. Soil–wall interface friction is defined carefully. The influence of suction on limiting passive earth pressures is analysed for two soils under steady state evaporation and infiltration. Suction increases the limiting passive stress at the soil–wall interface, with a dependence on the steady state flow type. The displacement of the retained soil is studied assuming the wall undergoes a rotation increment. The results show a clear difference in the displacement for evaporation and infiltration.     

雅鲁藏布江深厚砂砾卵石覆盖层钻探工艺

为了开展雅鲁藏布江流域综合规划及其水资源开发利用与保护专题研究工作,在雅鲁藏布江干流里龙坝址和本宗坝址共布置了4个200~300 m深的钻孔。主要通过在西藏高寒地区4个深厚覆盖层钻孔的成功实施经验,对西藏高寒地区深厚覆盖层勘探成孔工艺与技术进行研究探讨。     

大直径气举反循环成套钻具的研制

介绍了大直径气举反循环成套钻具的研制背景、设计原则、结构尺寸和主要技术参数。该套钻具不仅强度大,连接便捷,而且充分考虑了通气、通泥浆、泥浆补给三大通道面积等因素,采用内平设计。经生产试验,完全能满足大直径工程井气举反循环钻进的需要。     

56m深TRD工法搅拌墙在深厚承压含水层中的成墙试验研究

上海国际金融中心项目基坑面积约为48 860m2,开挖深度为26.5²7.9m,周边环境复杂。为控制抽降承压水对周边环境的影响,经方案比选,基坑周边设置厚700mm、深56m等厚度水泥土搅拌墙(TRD)作为承压水悬挂隔水帷幕。在上海地区施工如此深TRD墙体尚属首例,为此现场开展了试成墙试验,试成墙监测表明,墙身在深厚承压含水层中水泥土强度达到0.8427.9m,周边环境复杂。为控制抽降承压水对周边环境的影响,经方案比选,基坑周边设置厚700mm、深56m等厚度水泥土搅拌墙(TRD)作为承压水悬挂隔水帷幕。在上海地区施工如此深TRD墙体尚属首例,为此现场开展了试成墙试验,试成墙监测表明,墙身在深厚承压含水层中水泥土强度达到0.84¹.38 MPa。室内渗透性试验表明,渗透系数由10-3cm/s提高到10-7cm/s,满足隔水帷幕设计要求;墙体施工期间,地表最大沉降约8mm,主要影响范围约5m;土体侧向位移主要产生在距离墙体5m的范围内,TRD墙体施工对周边环境影响很小。试验墙体的顺利实施为后续正式墙体的施工提供了依据,也为类似工程提供了重要参考。     

GPS接收机内部噪声水平测试方法研究

阐述了在GPS精度鉴定系统中,针对短基线快速检核GPS接收机内部噪声水平测试方法进行研究,并结合试验验证了方法的可靠性.     

非理想流体自引力坍缩体系的熵变

本文利用共动度规讨论了非理想流体开放体系在自引力作用下的坍缩过程之熵变,结果表明,形成视界之前,体系的总熵不增,这说明黑洞的高熵产生于突变之中。