复合地层小半径曲线隧道盾构掘进参数统计分析

盾构机掘进参数在复合地层中的变化较为复杂,不同地质通常有不同的适用掘进参数。在小半径曲线隧道掘进中,管片错台问题尤为严重,而掘进参数对盾构姿态、管片拼装等有较大影响,合理的掘进参数有利于提高掘进效率,控制管片拼装质量,减少管片错台和裂缝,提高隧道运营的整体稳定性。以珠机城际轨道交通横琴隧道土压平衡盾构施工为例,针对区间典型地段的不同地层,分析了盾构掘进过程中的6个重要掘进参数和地层的相关性。     

复合地层中盾构掘进的姿态控制

在地质条件复杂的复合地层中,要保障盾构掘进顺利进行技术难度大,掘进方向与盾构姿态的控制困难.介绍了盾构姿态控制的基本概念,并从地质情况、盾构隧道设计、掘进参数、管片选型、成型管片上浮等几个方面提出了影响复合地层盾构掘进姿态的主要因素和控制措施,指出了在掘进参数控制方面存在的误区.     

盾构掘进富水硬岩地层管片上浮控制

盾构掘进富水硬岩地层管片上浮事故时常发生,严重影响盾构隧道质量和安全.通过以某地铁工程盾构隧道在富水硬岩段地层中掘进管片上浮控制为背景,首先,分析了富水硬岩地层盾构隧道管片上浮影响因素和成因机制,结合工程经验及本工程实际提出了管片上浮的预控措施;其次,采用ABAQUS仿真软件对本工程管片上浮进行模拟,在此基础上对管片上...     

小半径曲线盾构隧道下穿城市主干道施工技术

盾构隧道下穿既有道路过程中,不可避免地对地层产生扰动,施工前对下穿段范围内城市道路现状进行详细调查,掌握路面情况,选择符合施工情况的掘进模式。小半径曲线条件下盾构隧道施工,盾构司机需了解掘进线路的变化情况,根据地层变形的监测数据,控制盾构掘进参数,保证盾构掘进时的施工质量和管片拼装的施工质量。合理的推力和掘进速度是施工安全的重要保证。通过施工监测数据,分析地表沉降,及时反馈施工,优化掘进施工参数,可有效控制施工风险。     

大型泥水盾构越江隧道施工技术

阐述了人民路越江隧道新建工程江中圆隧道施工的关键技术,包括高精度隧道衬砌管片制造技术、大型泥水盾构掘进机、泥水分离处理系统、盾构出洞技术、盾构掘进管理、同步注浆技术、圆隧道内道路结构同步施工技术、特殊地层环境施工技术、联络通道施工技术等.     

成型隧道管片碎裂分析

盾构隧道管片碎裂影响着成型隧道的实体质量,也给隧道后续防水堵漏工作增加工作量,因此,分析、解决、控制管片碎裂是十分必要的。文章从盾构机械、所处地层、衬背注浆、盾构姿态及线路走向等影响因素着手,对盾构掘进过程中管片碎裂的现象、原因进行了分析研究,并提出了控制措施。     

某软土地层盾构隧道管片上浮事故分析

盾构隧道掘进过程中的管片上浮一直是一个棘手的问题。笔者以某软土地区盾构隧道工程中遇到的管片上浮事故为背景,寻找盾构机械参数、同步注浆、盾构姿态等方面的原因并进行分析研究,提出了相应的控制盾构隧道管片上浮的技术措施。实践证明,所采取的措施是可行、有效的,可为其他类似管片上浮事故提供借鉴与参考。     

区间盾构隧道曲线段掘进施工控制研究

曲线段盾构机掘进过程中容易发生管片错位、挤压破损及渗漏水等现象,或在纠偏大而引起地层大变形。以长沙地铁盾构隧道工程为例,研究了区间盾构隧道曲线段掘进中的控制要点。     

软土地层盾构施工控制要点及措施

结合软土地层盾构掘进施工实例,从盾构始发、管片拼装、姿态控制、同步注浆、地表隆沉及盾构到达等方面分析与研究,总结软土地层中盾构掘进施工中姿态控制要点及处理措施,为类似施工提供借鉴与参考。     

软土地层地铁盾构隧道施工引起衬砌结构变形规律研究

以无锡地铁3号线一期工程04标盛岸站至吴桥站区间盾构隧道为背景,基于海瑞克S-729土压平衡式盾构机掘进数据建立模型模拟盾构隧道开挖、同步注浆、管片拼装的流程。分析在软土地层中隧道衬砌结构的应力分布规律及拱顶、拱底与两侧拱腰在x, y, z方向的位移变化趋势,绘制在开挖过程中管片的变形分布曲线,结果表明盾构在软土地区掘进时,管片在拱顶、拱底与两侧拱腰处出现较大应力,同时拱顶与拱底处均在隧道竖直方向出现较大位移,而拱腰在隧道纵向位移达到最大值,须及时监控管片变形。     

浅析高速公路工程招投标中的最低评标价法

结合目前高速公路施工项目招投标活动的实际情况,阐述了最低评标价法的概念,归纳了其优点及存在问题,对完善最低评标价法提出几点策略,以期促进招标投标市场更加规范有序。     

Place-Making in Megaprojects in Melbourne

This article analyses state-led place-making practices in Melbourne. The two levels of government that influence planning in Melbourne make much of the city as ‘culturally vibrant’ and ‘creative’, and have incorporated creative city-inspired place-making principles into many layers of the planning system. An examination of the development of two mixed-use megaprojects in central Melbourne reveals however that ideals of culturally engaging public places, and indeed of creative landscapes for middle-class consumption, wither in the face of more basic imperatives for economic development. In these case studies the ‘creative city’, no matter how the idea is interpreted, has little traction either as a set of inclusive place-making principles or as a gentrification strategy. The article concludes that the creative city-inspired place-making objectives in the planning system at both state and local levels are ambiguous in their overall intents and completely unsupported by statutory controls. Such place-making objectives as are realised are the compromised results of the interplay of uncoordinated decisions, delivered at the pleasure of the developer.     

Pathogens in septage in Vietnam

Septage is widely acknowledged as a major source of infectious pathogens while disposal of septage, and the operation and maintenance of septic tanks, is not regulated in many developing countries. Twenty untreated septage and septage sludge samples were taken from Can Tho City, Vietnam to examine their pathogen content, and indicator micro-organisms. Escherichia coli and Enterococcus spp. were detected in all samples, regardless of sludge storage time. Phages were detected in 80% of samples. Salmonella spp. were detected in 70% of the untreated septage and 60% of septage sludge samples. Concentrations of phages and bacteria tested in septage sludge after many years of tank storage were much higher than the expected levels. Helminth ova were present in 95% of untreated septage samples with an average of 450 ova l^− 1, and were detected in all septage sludge samples with an average of 16,000 ova l^− 1. Twelve varieties of helminth ova were identified. More helminth ova varieties in higher concentrations were found in septage than those reported from stool samples. The varieties' frequency ranged from 10% to 50% and Ascaris lumbricoides predominated. Results show that pathogens and indicator micro-organisms, especially helminth ova, accumulate in sludge. Thus helminth ova should be considered when septage sludge is treated and used for agriculture. Proper health protection measures must be applied for people handling septage.     

在市场中实践在实践中学习在学习中进步--工程公司市场化进程的回顾与展望

近两年来，工程公司在提高市场竞争意识、推动市场化进程中做了大量工作，其中坚持走出去的方针是我们自我加压、推行加快市场化步伐的一个重要战略步骤。     

新时期广东城市化的新特点

新时期广东城市化出现以下特点:知识源导向、城市由单体向群体化发展、产业集群推动、政府主导自上而下的集约化发展、城镇化向城市化转变、由重“数量”发展向重“质量”发展的转变。     

新形势下高校强化基建财务管理的探讨

在市场条件下高校基建财务人员在加强日常财务管理的同时,必须树立起高度的工作责任心,抓好事前监督、事中监督、事后监督三个环节,全面理解、贯彻执行《高等学校财务制度》,管好用好各项基本建设资金,提高基建财务管理水平,更好地完成高校各项基建任务,以有限的投资,最快的建设速度,获得最大的投资效益。     

2005年北京办公物业市场七大趋势

趋势一:CBD区域写字楼集中放量从各区域规划方案上看,CBD区域多数项目在03～04年处于项目的报批手续及拆阶段,预计2005年正式推向市场,因此2005年CBD区域将成为北京市场供应集中的域,区域即将供应的项目有北京财富中心(二期)、金地国际花园、万达广场、SOHO尚都、万通中心、世纪财富中心、怡禾国际中心、光华国际等。除去未知项目,2005CBD写字楼办公面积的供应量为60万平方米左右。中关村区域经过一段时间的集中供后开始逐步放缓,2005年供应的体量相对较大的项目有中关村金融中心、新中关。金街区域可能开盘的项目只有2个:英蓝国际中…     

浅谈我国工程项目建设成本控制存在的问题

结合目前我国施工企业工程项目成本管理现状,对工程项目成本管理过程中存在的问题进行了较详细的分析,并提出了一些解决问题的办法,以做好项目成本控制工作,进而增强企业经济实力。     

Variation in property taxation in Tulsa

Conclusions It may be reasonably concluded from this study that the range of variation in these ratios of assessed to actual value are of a reasonable size for the great majority of cases. The frequency distribution of these sample ratios was not normal, however, as was assumed a process of this type would produce. On the other hand, the failure of the regression analysis to identify any significant variables which would explain these variations would tend to re-enforce the assumption that the fluctuations were indeed of a random nature.To sum it up in one paragraph, aside from a few extreme cases, the assessing process appears to give estimates which are more consistent than would be expected under the assumption that any errors would be of a random nature, but the regression analysis was unable to isolate any particular socioeconomic characteristics which would explain the variation which was present.Financial support for this research project was furnished by the University of Tulsa.