基于Midas GTS岩土有限元软件模拟基坑降水对周围建筑物沉降的变形

随着城市化进程的加快,在建筑密集、地下水位较浅的地区出现了越来越多的深基坑工程,不可避免地涉及到基坑降水对周围建筑物沉降的影响。虽然基坑降水可以为基坑开挖提供更为便利的条件,但同时也会导致周围土壤支护结构和水压的变化,降水可能导致基坑渗漏,从而产生流沙、流沙等现象,严重时会导致周边建筑物的沉降。以昆明市某基坑降水工程为例,利用MIDAS-GTS有限元分析软件对基坑降水引起的周边建筑物沉降进行数值模拟。在降水过程中,建筑物下方6m处孔隙水压力呈线性下降,距基坑15～22m范围内,孔隙水压力由10.1kPa降至7.82kPa,说明降水井的影响范围随降水井距的增大而减小,截水帷幕后的土体沉降可以有效地控制。通过设置截水帷幕来控制。综上所述,模型计算结果与实际情况吻合较好,对今后的实际工程具有一定的参考价值。     

翻车机房降水保护设计及效果分析研究

依托曹妃甸某翻车机房工程对场区赋存的潜水层及承压水层进行地下水参数探明,根据施工降水的影响半径与周边构建筑的平面关系针对性的提出了降水保护设计,通过对降水过程的效果分析研究,得出了止水帷幕与回灌井不同工艺的效果差异,保障了基坑工程的顺利实施,并且为类似工程提供了经验参考。     

围护结构变形与相邻建筑物沉降控制措施

在城市建筑密集区域进行深基坑施工时,其围护结构的变形对周围建筑物的安全性能影响十分重大。结合天津地铁3号线北站站基坑施工,通过监控、降水、控翩开挖与支撑施工、止水、地基加固等措施,控制深基坑围护结构的变形及对相邻建筑物沉降的影响。结果表明,本工程深基坑成为无渗漏基坑,确保了基坑和周边建筑物的安全。     

深基坑降水设计及其优化

文章以翻车机房深基坑工程为例,针对初始降水设计方案进行了多组抽水试验,验证场地的水文地质参数,校检降深结果能否满足主体土方开挖及结构施工的要求。根据试验结果,对降水设计进行了优化,结果表明：优化后的井管结构,特别是采用混合井替代部分疏干井与减压井,降水效果更为明显,保证了本基坑工程的安全顺利实施。     

天津港某翻车机房水文地质条件及基坑地下水控制方案探讨

本文通过野外钻探、现场抽水试验及室内试验等综合方法研究了天津港某翻车机房工程水文地质条件,对基坑地下水控制方案进行了探讨。     

考虑渗流影响的深基坑开挖模拟与监测分析

某专业化煤炭码头翻车机房圆形深基坑地下水位较高且临近办公楼,基坑开挖安全需着重考虑地质条件、地下水位及周边环境的影响;结合此基坑开挖监测实例,应用有限元软件模拟基坑分步开挖时渗流及近接建筑物对基坑稳定的影响,并利用仿真结果指导监测点位的布置及监测方案优化;仿真结果显示,考虑渗流作用时,土体内的有效应力值增加,基坑开挖时邻近建筑物地连墙顶部将产生22 mm侧向位移,距离地连墙10 m处产生59 mm沉降,土体孔隙水压力随施工进展逐渐消散;监测结果与计算结果差异较小,考虑渗流作用的有限元模拟能很好地对高水位基坑开挖进行仿真分析,建议在进行高水位深基坑变形计算时考虑渗流引起的有效应力的变化。     

中共“一大”会址纪念馆扩建工程基坑围护工程设计总结

本文对“一大”会址纪念馆扩建工程基坑围护设计进行了总结，并详细介绍了采用基坑内“被动区跟踪双液注浆”对坑外土体进行挤压加固以控制并纠正建筑物沉降的方法；本工程采用该技术使老“一大”会址在新馆基坑挖期间沉降控制在１０ｍｍ以内，成功地保护了这座国家级重点保护建筑；受到了市委、市政府领导的好评。并且为今后周边环境保护要求较高的基坑工程提供了很好的经验。     

日照港某翻车机房围护结构拆除方法比选

日照港石臼港区某翻车机房围护结构工程依施工顺序由圆形地连墙及廊道地连墙、基坑帷幕灌浆截渗结构、翻车机房主体结构地基处理、廊道主体结构地基处理、基坑支撑系统五部分组成。翻车机房主体结构施工时需要对部分围护结构进行拆除,包括部分地连墙和支撑结构,拆除方法主要包括绳锯切割、爆破拆除2种拆除施工工艺,现进行对比分析[1]。通过对深基坑内支撑拆除施工工艺的研究,可以进一步提升对深基坑内支撑形式的认识,同时对后续的类似施工提供借鉴,以便更好的指导施工生产,提高施工效率与质量。     

黄骅港一期工程翻车机房地连墙施工技术

介绍黄骅港翻车机房围护结构地下连续墙施工技术和地基降水方案。     

基坑降水引起地面沉降分析

基坑降水引起地面沉降问题在各类工程实践中相对比较常见,甚至会对周围建筑物产生影响,使其出现裂缝、坍塌等问题。无论工程设计人员,还是一线施工人员都要结合工程实际,对土体结构和地面沉降机理具备清晰的认识,参照土体力学指标对沉降量予以计算,保证施工安全。文章依据具体工程背景,分析地面沉降形成机理,预测沉降量,针对基坑降水引起的地面沉降问题提出具体对策。     

Errata

正In the paper"Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar,India"in Vol.12,No.4,Page:509,References were lost,and the two authors’biographies were identical.The correct text is shown below.We apologize to the authors and our readers for any inconvenience caused by the errors.     

Journal of Marine Science and Application 2014 Sum. Contents

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第34届海洋、离岸及极地工程国际会议(英文)

正St.John's,Newfoundland,Canada,May 31-June 5,2015 OMAE2015 is the ideal forum for researchers,engineers,managers,technicians and students from the scientific and industrial communities from around the world to: meet and present advances in technology and its scientific support;     

联合作战计划和执行系统

全球指挥控制系统(GCCS)实施当前美国海军网络中心战信息基础设施的联合计划网络。联合作战计划和执行系统(JOPES)支持GCCS实现联合计划。JOPES有两类计划：时间不限的精密预案计划生成作战计划、方案计划或职能计划；时间敏感的危机行动计划生成作战命令或战役方案。前者在和平时期创建的作战计划是后者的计划基础，加速应付危机的能力。     

Eastbound or westbound ?

In terms of equal sailing distances, where is the inflexion when ships depart from ports in the Asian Continent to New York via Suez and/or Panama？
The answer is China South Port Group （Hong Kong, Shenzhen and Guangzhou）.     

Recent progress on wave induced loading measurements in warships

Recent measurements of wave induced hull strain and flexure in RN warships are presented together with the derivation of the current design criteria for extreme hull girder bending loads. The history of the development of the shipboard instrumentation used is given and recent developments to improve the quality and ease of analysis of the data are described. An unexpectedly high transverse asymmetry in the longitudinal strains measured in destroyers is shown to be the result of a combination of vertical and lateral bending in oblique seas. Finally recent theoretical comparisons between the loading of Deep-Vee hulls and conventional UK rounded bilge hulls are presented which demonstrate the higher loading experienced by this type of hull form.     

桥梁防撞设施物理模型试验

物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。     

印尼某电厂码头水工建筑物设计

印尼某电厂项目码头水工建筑物包括码头、防波堤和护岸等主要组成部分。在该项目水工建筑物的设计过程中,综合考虑当地的自然条件、施工能力和材料来源等因素,不断优化结构选型和结构断面。根据不同使用要求,护岸分别采用直立式和斜坡式2种结构型式,推荐的设计方案节省投资、施工方便,可供同类工程设计参考。     

Impact of regulation on the performances of long-distance transport services: A comparison of the different approaches in Sweden and Norway

Despite the many socio-economic similarities between Sweden and Norway, differences in jurisdiction, organisation, cooperation, and financing of long-distance passenger train and coach services have led to the development of four distinctively different ways of serving the markets. This paper describes how the train and coach markets have developed in the two countries, with emphasis on regulatory and industrial structure and a couple of performance variables.Looking at passenger rail, both countries separated infrastructure from operation over a decade ago. However, while Norwegian rail is characterised by an almost monopoly supplier, rail services in Sweden are partly decentralised to the responsibility of county authorities and are widely subjected to competitive tendering. The rest of the network is about to be opened up for on-the-track competition. Swedish Rail (SJ) has spent the last decades consolidating its core business (passenger rail) and sold out its other businesses. In contrast, the Norwegian state rail (NSB) has expanded its business to become a major bus operator and property owner, with extensions also into the Swedish market.The coach industry was more recently deregulated in both countries. The Swedish coach market is dominated by privately owned companies operating services to and from Stockholm. In Norway, state-owned NSB is a major coach operator on medium distance routes, and is also the largest partner of Nor-Way Bussekspress which totally dominates long-distance coach services. Further, the Norwegian coach market is characterised by cross-ownership and cooperation which has enabled an extensive route network which covers most of Norway.We find distinct differences in achievements in the two modes and in the two countries. Swedish rail services have succeeded in winning market shares and in renewing and developing both infrastructure and service levels to a greater extent than the Norwegian model. On the other hand, the Norwegian coach market seems to be more developed and efficient compared to its Swedish counterpart.The paper concludes with a discussion on the possible links between the different approaches and the performance observed, with the aim to stimulate further and more detailed research on some important issues.     

开放式数据挖掘系统模型

目前国内已经出现了少量的数据挖掘相关产品。国内数据挖掘软件无论从数量还是质量上比较，都与国外软件存在着较大的差距。随着数据仓库技术的普及，数据挖掘应用的需求越来越强烈，如何缩短这种差距，研发数据挖掘软件产品成为国内业界的一个重要问题。通过引用目前国际通用数据挖掘标准技术来构建开放式的数据挖掘系统模型，该系统模型从可扩展性、可重用性、易用性等方面得到了加强。