地铁盾构隧道下穿加油站的地表沉降分析

随着城市快速发展,地铁建设随之迅猛发展,地铁隧道穿越城市的周边环境日趋复杂。以青岛地铁区间盾构下穿加油站为例,盾构左线正穿加油站油棚、办公房,侧穿4个油罐,油罐埋深3.5 m,距隧道拱顶约11.3 m。盾构机穿越加油站办公区时,监测速率沉降报警,通过调整盾构参数、保压施工、二次注浆和渣土改良等措施。地表和油罐的沉降变化速率与累计量均在安全可控范围内,盾构机已安全穿越加油站,为今后盾构穿越类似地层的重大风险源提供参考。     

盾构同步注浆量对地层变形的影响

同步注浆作为盾构隧道施工中普遍采用的地层沉降控制方法,其参数设定对地层沉降控制效果具有显著影响。以湖南省长沙市地铁4号线碧沙湖-黄土岭区间右线最浅埋深断面为例,在有限元分析软件ABAQUS中建立二维地层-隧道结构模型,模拟盾构隧道同步注浆过程并分析结果,对同步注浆量与地层沉降量的关系进行研究,给出施工中盾构隧道同步注浆用量建议。     

富水砂卵石层临近既有桥墩常压开仓施工技术研究

在开展地铁盾构施工时,因设备原因需要开仓检修刀盘时受到诸多不利因素的影响,尤其是在面对不具备带压进仓富水砂卵石地层及邻近既有桥墩的环境下,需要通过施作隔离桩及袖阀管注浆加固保证既有桥墩安全、刀盘前端施作排桩并辅助降水保证掌子面地层稳定,从而创造安全稳定的进仓条件。在本文中,则结合盾构隧道工程实例,着重对其中的建立常压开...     

地层铁路隧道建设中大断面富水复合地层的施工技术

某地铁盾构施工工程,项目线路多穿越软硬不均复合地层,其中部分线路采用浅埋暗挖法开挖,以现场监控的方式掌握暗挖区间隧道地表沉降情况。探寻其沉降的分布特点以及变化规律,提出土压平衡盾构法。总结此工法在施工中的重点和难点,阐述具体操作工艺。实践表明,标段区间盾构施工质量达标,复合式土压平衡盾构具有可行性。     

盾构隧道穿越建筑物安全性评估及控制措施

盾构隧道穿越建筑物的施工修建方式在地铁工程中越来越多,对所穿越建筑安全影响及施工质量标准要求也在不断提高。为此,对盾构隧道所穿越建筑物的安全性影响评估及控制措施进行分析,并做出整理和总结。     

顶管法施工对地铁隧道的影响分析——以深圳某区间隧道施工为例

为研究大直径顶管上跨施工对地铁运营隧道的影响预测问题,以深圳地区1.8m大直径顶管上跨地铁1号线某区间隧道施工为例,采用MIDAS/GTS三维有限元软件建立三维数值模型,对顶管施工引起的地表隆沉、地铁隧道竖向位移和横向收敛变形、顶管隧道本身竖向位移进行数值模拟分析。分析结果表明,顶管施工过程中,由于土体开挖卸载引起下部土体向上回弹,导致地面会发生一定的隆起,最大隆起发生在顶管隧道两端,中部隆起位移较小;地铁隧道水平位移很小,竖向发生向上位移,并伴随横向收敛变形,导致地铁隧道发生竖椭圆变形,但其位移均在地铁保护的允许范围内;顶管隧道本身会发生竖向向上位移,易导致顶管隧道前端产生偏移。该结论可为类似工程施工项目提供参考。     

盾构穿越暗挖风道施工技术分析

地铁施工采用盾构技术施工过程中,由于暗挖风道跨度比较小,作业空间相对来说也较小,增加了盾构二次始发、盾构穿越姿态控制的难度,进而导致施工风险增加。以实际工程为例,分析和探讨地铁盾构穿越暗挖风道的施工技术。     

地铁车站暗挖逆作法地表沉降控制技术

分析地铁车站主体施工阶段地表监测数据,总结一次扣拱暗挖逆作法施工过程中的地表沉降变形规律,提出控制地表沉降变形的有效措施,已达到控制风险,减少地层沉陷等安全事故发生的目的。     

地铁盾构穿越高层建筑钢管隔离桩施工技术

在地铁盾构区间的设计中,下穿高层建筑施工难度较大,采用钢管隔离桩施工技术,减小施工地面及高层楼房基础沉降,以达到安全可控顺利穿越高层建筑的目的。     

复杂地层盾构施工对地表建筑物变形研究

以实际工程为背景,研究复杂地层中盾构施工对其侧穿浅基础建筑物的地表变形影响的特点,并对复杂地层中盾构施工对侧穿浅基础建筑物沉降预测分析,得到对复合地层中盾构侧穿浅基础建筑物所引起的施工变形影响较大的因素,给出有针对性、有效的施工应对措施,建立一套复杂地层盾构隧道施工对侧穿浅基础建筑物的施工变形控制技术,为类似工程提供指导。     

Comparing FTTH access networks based on P2P and PMP fibre topologies

There is an ongoing discussion in the market which Next Generation Access (NGA) architecture best suits future needs and which investment and cost differences exist. The discussion can be subsumed as P2P vs. GPON, which is somewhat misleading as this article reveals. The discussion is driven by the fact that the high capital cost and the long asset life time of fibre mean that the technology choices made today will dominate the opportunities for telecommunication business of all market players, incumbents, competitors, content providers and business and residential users for many years in the future.The paper analyzes the cost and other differences between Fibre-to-the-Home (FTTH) access network architectures and their related different wholesale approaches by using the well-known and understood steady state approach applied in other NGA analyses in the past. In addition to the steady state analysis a dynamic cost evaluation is included taking into account the different investment behaviour of the FTTH architectures over time. The results describe investment and cost differences between architectures, incumbents and wholesale based competitive operators. The analysis has been performed for different geotypes (clusters) of decreasing population density in a representative European settlement structure.     

Divergent patterns of engagement in Internet standardization: Japan,Korea and China

This article analyzes the engagement of Japanese, Korean and Chinese participants in the development of Internet standards at IETF on the basis of four quantitative metrics: attendance, patenting, authorship and leadership. The results are strikingly divergent. Japanese involvement in Internet standardization began early and Japan was, for many years, second only to the U.S. in terms of IETF participation. Though Japanese participation has declined since the early 2000s, Japan remains a major contributor to IETF standardization. Korean involvement in IETF has always been significant, but below the levels of Japan and major European countries. Korean participation in IETF has also declined over the past decade, and has been dominated by one firm, Samsung. Though meaningful Chinese involvement in IETF did not begin until the mid-2000s, it has rapidly expanded in recent years. Today, China is a major player in numerous areas of Internet standardization in terms of three metrics (participation, patenting and leadership), and is rapidly gaining in terms of document authorship as well. Most of China׳s recent IETF involvement can be attributed to Huawei, though other Chinese firms have recently begun to increase their participation in the organization. Thus, contrary to some views that China׳s engagement with standardization is primarily one of indigenous innovation and “catching up”, China׳s experience with IETF demonstrates deliberate and effective engagement with a major Western standards-development organization on its own terms.     

快速成形技术的应用及热点分析

基于快速成形技术的原理,展示了快速成形技术在快速模具制造、金属零件直接成形、反求工程等领域的广泛应用,总结了快速成形制造技术研究的热点,即研发新材料和新设备、提高成形精度、建立RPM的反求工程系统、建立成形技术的统一标准和扩大成形技术的应用领域。     

Whose Image is it Anyway?: Some Considerations of the Curricular Importance of Subject Image in Secondary School Design and Technology Education

This paper explores the idea that a sense of school subject image is a necessary feature of curriculum management and a potent force for change. The discussion centres on the view that all school subjects have an image and that if those intimately involved with the subject do not control the image then someone else does! In such circumstances the image is the product of past encounters and old euphemisms and is unlikely to hold the changed realities.The UK developments in Design and Technology education (the term Design and Technology is used to denote the school subject defined under this heading by the UK National Curriculum, 1995) have created something of an image problem which has interesting international parallels. Some of these problems are due to clearly discernible internal tensions and an ambiguous relationship with other subject areas.Through greater attention to subject image internal controversies might be acknowledged and resolved, relationships with other subject areas can be more meaningfully understood and practitioners can be helped to make sense of curriculum change.     

Indigenous peoples’ nutrition transition in a right to food perspective

In indigenous communities the nutrition transition characterized by a rapid westernization of diet and lifestyle is associated with rising prevalence of chronic disease. Field work and literature reviews from two different policy environments, Argentina (Jujuy) and Canada (Nunavut), identified factors that add to indigenous peoples’ disease risk. The analytical framework was the emerging human right to adequate food approach to policies and programmes. Indigenous peoples’ chronic disease risk tends to increase as a result of government policies that infringe on indigenous peoples’ livelihoods and territories, undermining their economic system, values and solidarity networks. Policies intended to increase food security, including food aid, may also fuel the nutrition transition. There is a need to explore further the connection between well-intended policies towards indigenous peoples and the development of chronic diseases, and to broaden the understanding of the role that different forms of discrimination play in the westernization of their lifestyles, values and food habits. Food policies that take due account of indigenous peoples’ human rights, including their right to enjoy their culture, may counteract the growth of chronic disease in these communities.     

HSE走进中国石油

企业管理水平的好坏直接影响着企业的经济效益,运用HSE管理能提高企业管理水平,HSE管理模式将健康,安全,环境三者视为一个有机的整体。HSE管理认为人的安全是第一位的,人是创造财富的原动力,是企业的最大财产,HSE管理体系强调的是“蝴蝶效应”。     

A strategic skill based model of supplier integration and its effect on supply management performance

Supplier integration is a tool to help organizations gain competitive advantage. Strategic supply management skills and the supply management function's perceived status are hypothesized as antecedents to supplier integration leading to supply management performance. The sample for this study includes 152 executive level supply management professionals. The empirical results suggest that strategic skills and perceived status are essential antecedents to supplier integration and subsequent performance. Further, the relationship between strategic skills and performance is mediated by supplier integration. Results of a dominance analysis also suggest which strategic skills are most likely to explain status integration, and performance. These findings have significant implications for supply management theory and practice.     

Cost allocation of WCDMA and wholesale pricing for mVoIP and data services

This study estimates cost-based prices for wholesale voice and data services provided to 3G (WCDMA) MVNOs according to their distinct types. For estimation, 3G MVNOs are classified into different types, and the overall cost of WCDMA facilities are separated into voice and data components based on their subscriber rates, actual traffic rates, as well as efficiency consideration of traffic rates. The study then calculates cost-based wholesale prices of voice and data services for each of the 3G MVNO types. The result of this study shows that a cost-plus pricing scheme can help achieve the policy goals of the regulator, namely, lowering telecommunications tariffs and facilitating the introduction of new convergent-type services, far more effectively than the current retail-minus pricing scheme. The findings of this study may assist firms in developing business models based on 3G networks and telecom regulators in designing policies related to interconnection, mVoIP, prepaid calls, wholesale services, and network neutrality.     

Collectivism,individualism, and outgroup cooperation in a segmented China

A consistent theme in cross-cultural management research is that collectivists are more cooperative than individualists. We use Hofstede's measure for individualism–collectivism and combine it with an experimental measure of cooperation to test this relationship in China. In contrast to the established paradigm, we find that groups with higher individualistic scores are more cooperative than those groups with higher collectivistic scores. We attribute these results to groups being composed of outgroup members. In addition, we find that subjects from the more developed coastal area are more individualistic and cooperative than are subjects from inland China.

Material power and normative conflict in global and local agrifood governance: The lessons of ‘Golden Rice’ in India

This special section aims to investigate the interaction of global and local forces in shaping agrifood governance. It starts from the recognition that a multitude of actors and norms shape today’s agrifood system. The resulting opaqueness of the systems makes it extremely difficult to understand and explain processes and outcomes of agrifood governance. Given the sustainability challenges facing the agrifood system, improvements in our understanding of what the interaction of global and local actors and norms means on the ground are urgently needed, however. The section, therefore, analyses agrifood governance in India across a selected group of cases. It does so by employing a systematic framework emphasizing the material and ideational dimensions of power and their interaction. The section has chosen India as the setting in which to analyze this interaction due to the crucial role the food demand and supply of this rising power plays in today’s agrifood system. This article provides the special sections’ analytical framework, which uses the interplay of material and ideational dimensions of power as a focal lens. In addition, the article applies this framework to an empirical study of the political conflict around GMO foods in India, specifically the case of ‘Golden Rice’.