强夯法加固地基处理在皖南山区（泥质砂岩填土）的应用

强夯法是利用夯击能,使地基土得到夯实挤密,从而改善性能,提高承载力和压缩模量。皖南山区泥质砂岩填土采用强夯法地基加固,是一种提高地基承载力明显,经济而又科学的地基处理方法。     

强夯加固粉土与粉质粘土互层地基

强夯法处理地基技术工艺简单,造价低,效果显著,应用非常广泛。强夯法处理深厚粉土,通过孔隙水压力试验、分层沉降环和载荷板等原位试验评价了强夯的加固效果,获得了强夯法加固该工程的单击夯击能、单点夯击数和每遍夯时间间隔等施工参数,从而有效的指导强夯法处理地基的施工。     

高真空击密法加固青岛地区软土地基试验研究

结合青岛高新技术产业开发区的软基加固处理实践,对高真空击密法加固饱和软土地基在本地区的加固效果进行了研究。通过对加固处理过程中土体的超静孔隙水压力变化,变形、承裁能力变化等进行监测,并对大面积施工过程中各参数包括强夯的夯击能、有效加固深度、务击闻隔时间、夯击次数和遍数、真空降水的时间等进行优化分析,试验结果表明高真空击密法能充分发挥强夯和真空降水的优点,有效加固了土体。     

机场弱膨胀高填土浅层强夯加固参数设计

根据弱膨胀土的变形特征和施工特点,讨论并确定了弱膨胀高填土浅层强夯加固处理的原则和参数设计。结合工程实际,提出了确定夯击能量、夯击次数等主要参数简便易行的工程方法。现场测试结果表明:该方法能在短期内完成浅层填土固结沉降,有效提高地基强度,缩短工期,降低工程造价。     

动力排水固结加固淤泥地基的关键技术研究

为了保证广州南沙泰山石化一期淤泥地基处理工程的质量,采用现场试样的方法,对动力排水固结法处理淤泥土地基的关键技术—动力工序和排水系统的设置进行了研究。结果表明,对深厚淤泥地基,水力吹填粉细砂作为强夯垫层时,在设置合理的竖向和水平排水系统的基础上,宜采用低能量"少击多遍,逐层加固"的动力施工工艺,每遍点夯的夯击能量应控制在1000(kN·m)内。加固后的土体物理力学指标均有一定程度的改善,整体加固效果很好。该成果对类似的软土地基处理工程有一定的借鉴和指导意义。     

强夯地基处理在海勃湾水利枢纽土石坝工程中的应用

为了解决海勃湾水利枢纽土石坝桩号坝1+388～坝1+604段坝基土层的震动液化问题,地基液化层厚度小于6m采用强夯处理,强夯地基处理施工利用50t履带式吊车等设备,现场通过不同单击夯击能、夯点间距的生产性试验确定施工参数后进行规模施工,经质量检测,该施工方法成功解决问题,不仅降低了施工成本,而且推动了施工进度。     

浅谈强夯在京沪高速铁路地基处理中的应用

基础处理强夯法适用于处理碎石土、砂土、低饱和黏性土与粉土、湿陷性黄土和低含水量软土、人工土石混填土和素填土等地基,也可以用于防止粉土和粉砂的液化,并适用于高速铁路软弱地基浅层处理,消除或降低大孔土的失陷等级。基础处理强夯法是利用起重设备将具有一定重量的夯锤吊起,从高处自由落下,对地基进行反复夯击,给地基以强烈的冲击和振动,使得土空隙中的气体和液体排出,迫使土体孔隙压缩,使土粒结构重新排列,从而提高了土的承载力,降低其压缩性。     

真空动力固结加固吹填土地基的试验

结合河北省某大面积吹填土地基处理工程,对真空动力固结在加固含饱和粉质黏土夹层的吹填土中的工艺参数进行了现场试验研究.通过对加固过程中超静孔隙水压力、深层沉降、强夯工艺参数等的分析研究,探讨了真空动力固结应用于含淤泥质粉质黏土夹层吹填砂土的加固机理.试验研究表明,真空动力固结处理吹填土地基取得了良好的加固效果,可为类似工程提供借鉴和指导.     

机场挖填交界基础的强夯处治效果及参数分析

结合湖南郴州机场挖填交界区域路基工程实际,基于强夯处置路基加固机理,应用强夯法处理挖填交界面,开展夯击能为2.5 MN·m和3.0 MN·m,夯点间距为4.0,4.5和5.0 m的强夯处置现场试验,分析填土级配、强夯变形量及固体体积率的变化规律,探究不同夯击参数作用下的地基处理效果,提出最优夯击参数并研究在最优夯击参数条件下挖填交界面的差异变形特征。研究结果表明:填方区采用夯击能为3.0MN·m点夯2遍+1.0 MN·m满夯1遍,夯点间距为4.0 m;挖方区采用夯击能为2.5 MN·m点夯2遍+1.0MN·m满夯1遍,夯点间距为4.5 m;强夯处理后挖填交界处的差异变形量仅为0.02 m,固体体积率相对差为0.5%,每层填筑厚度4 m满足有效加固深度要求,设计参数可以为其他相似填料处治地基工程提供参考。     

真空预压联合电渗法处理高含水率软土模型试验

针对海相吹填土高含水率、高压缩性、低渗透系数的特点,提出了采用真空预压联合电渗法的地基加固方法,并通过室内模型试验对该工法的加固机制进行了初步探索.试验结果表明:初期采用真空预压排水,当试验土体达到最佳临界含水率0.85后,联合电渗法可有效地加快地基排水速度;采用真空预压联合电渗法处理吹填土,土体通常会产生较大的竖向和...     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.