双侧卸载工况下盾构隧道错缝拼装结构变形特征

依托厦门地铁2号线区间隧道,采用相似模型试验和有限元数值模拟分析了隧道双侧卸载工况下结构的受力变形特征、破坏形式及损伤过程,得到盾构隧道管片错缝拼装结构在双侧卸载工况下的变形控制指标.结果表明,管片混凝土裂缝宽度达到设计允许值0.15 mm时的收敛变形值为3.29‰D(D为隧道直径);螺栓屈服时收敛变形值为10.67‰D,结构破坏形式表现为由管片开裂、螺栓屈服直到变形过大并垮塌.     

地铁低瓦斯区间小间距重叠隧道大直径盾构施工技术

针对成都地铁18号线天府新站-龙泉山隧道进口端盾构区间和合江车辆段出入线组成的上下重叠隧道进行了施工技术研究,提出了"下部隧道盾构掘进参数控制+下部隧道围岩和夹层土体注浆双加固+下部隧道内设管片支撑结构+上部隧道盾构掘进参数控制"施工措施,建立了地铁区间小间距重叠隧道大直径盾构施工技术。经管片支撑结构应力、地表沉降和下隧道管片结构变形监测结果分析,验证了建立的技术的可行性,安全快速地完成了施工任务,对今后类似工程提供参考。     

地铁盾构隧道30°斜穿地裂缝的物理模拟试验

为了研究30°斜穿地裂缝的盾构隧道管片衬砌结构在地裂缝影响下的变形破坏模式和影响规律,从西安地铁盾构隧道工程背景和西安地裂缝地质环境出发,根据相似理论设计了盾构隧道管片衬砌结构模型试验的相似常数,对模型混凝土、模型钢筋、结构围岩、模型管片及其连接螺栓参数等进行了设计.该结构模型试验能对结构钢筋、混凝土进行应变测量,对结构接触土压力和结构外围土压力、结构内部收敛位移、模型顶表面土体变形等进行观测.借助地基沉降试验平台,通过自锁式千斤顶的缓慢下降,实现对地裂缝上盘相对下降的模拟,地裂缝的活动速率和错动量通过工控机控制自锁式千斤顶的运行速率和行程来实现.试验结果表明:该试验设计满足地裂缝活动下30°斜交盾构隧道管片衬砌结构变形破坏模式和破坏范围研究的需要,能实现模型试验目标;地基沉降试验平台能较好地模拟地裂缝的活动.     

北京地下直径线大直径盾构隧道技术研究

以北京地下直径线双线大直径（11.6 m）盾构隧道的设计技术研究为背景,重点介绍了该盾构隧道的盾构选型、盾构管片结构计算、管片结构设计、管片防水设计等技术,并对该盾构隧道施工的设计要求做了简单叙述,对今后类似工程具有一定参考价值。     

盾构隧道衬砌结构小角度斜穿地裂缝的破坏机理

从西安地铁1 #线工程背景和西安地裂缝地质环境出发,根据相似理论设计了盾构隧道管片衬砌结构30°斜穿地裂缝的物理模型试验管片混凝土应变、纵向和环向螺栓应变、结构接触土压力外围土压力、结构内部收敛位移、模型顶表面土体变形以及宏观变形破坏现象表明:盾构隧道管片衬砌结构30°斜穿地裂缝的变形破坏模式为剪切变形为主,局部有扭转变形;结构破坏范围为上盘1.25D,下盘0.75D(D为管片环外径);管片衬砌结构变形破坏不对称,管片环向处于偏压状态;环缝拱底位错量大于拱顶和拱腰,拱底最大位错量达40 mm(0.033D),模型难以适用地裂缝错动变形20 cm(0.1667 D),盾构管片衬砌结构不适用于地裂缝活动强烈的地质环境     

盾构隧道下穿明挖区间隧道三维数值模拟分析

某地铁工程正线盾构隧道需下穿引出段线明挖区间隧道,针对上部隧道底部不加固、上部隧道底部加固及上部隧道底部不加固+盾构反向掘进三种不同工况,对盾构掘进中引起的周围土体变形及上部明挖区间隧道位移进行了详细分析。计算结果表明:上部隧道底部土体加固能控制上部隧道沉降变形,但加固对新建隧道及其周边土体变形影响很小;因上部隧道在平面上为曲线型,盾构掘进方向对上部隧道有一定的影响,对新建隧道管片及周边土体变形影响较小;采用注浆加固后,上部隧道沉降变形得到了较好地控制,最大可降低10%的沉降,同时可根据具体控制要求,选择合适的加固强度。     

盾构姿态变化对管片影响与控制研究及展望

大量盾构隧道工程实践表明,盾构姿态控制不良导致千斤顶对管片的偏心推力、盾壳对管片的挤压力、盾尾注浆对管片的不均匀压力等施工荷载是引起管片结构发生各种病害的主要原因.为了阐明盾构姿态变化对管片受力的影响及控制技术的应用现状,详细介绍了盾构姿态参数、测量方法及姿态变化过程,重点阐述了盾构姿态引起施工荷载的变化对管片结构影响的研究进展,并归纳施工各阶段盾构姿态的控制和纠偏技术措施,指出了现有研究的不足和尚需讨论的问题.建议研发高精度高智能化的自动导向系统,全面考虑姿态变化过程中的施工荷载,构建精细化管片模型和三维盾构姿态的动态模型,进一步探究姿态参数对盾构姿态的控制效应.     

苏州市轨道交通3号线重叠隧道盾构掘进参数控制值研究

依托苏州市轨道交通3号线土建Ⅲ-TS-14标现娄区间重叠隧道工程特点,详细介绍了管片衬砌结构设计和施工组织技术,选取重叠段中间50环管片对应的盾构掘进参数进行了统计分析,包括掘进速度、同步注浆压力与注浆量、土舱压力、盾构推力与扭矩、刀盘转速、出土量、二次注浆压力与注浆量,解决了软土重叠隧道盾构掘进参数控制值问题,为今后类似工程提供技术指导。     

地铁盾构施工过程中变形与结构失效机制研究

随着越来越多的地铁盾构隧道的建设和运营,地铁盾构施工过程中的变形和结构失效引起了更多的关注.首先介绍了盾构结构的管片结构以及接头构造,其次,分别讨论了隧道运营过程中产生的不同横向变形和纵向变形并推导出了相关变形公式;最后,根据其横向变形以及纵向变形对隧道产生影响,分别阐述了由变形造成的管片缝隙张开失效、接头处螺栓受拉受剪失效、隧道由于人工原因漏水失效等情况.     

小曲率隧道盾构关键技术及发展现状

21世纪是地下空间开发利用的世纪,地下轨道交通成为争先推动的重点之一,其对缓解交通压力有着不可替代的优势.因盾构隧道施工具有自动化程度高、掘进速度快等优点,在目前地下轨道交通修建中被普遍采用,特别是小曲率盾构区间因其线路适应性强,更是未来地下空间开发利用的重要支撑.与直线隧道相比小曲率隧道的力学性能更加复杂,会给盾构管片设计带来前所未有的挑战.首先总结剖析国内外几种常见的盾构管片衬砌计算模型及相关试验方法,分析当前典型模型的优缺点,进一步开展小曲率半径掘进区盾构管片的现场试验,提出小曲率隧道盾构设计关键技术,有望对未来地下轨道交通的小曲率区间盾构设计提供理论指导与技术支撑.     

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.     

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)

正~~     

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).     

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.     

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.