桩锚-土钉复合支护在基坑临近桥墩防护中的应用

以乌鲁木齐轨道交通2号线高铁站基坑支护方案变更为背景,梳理桩锚-土钉复合支护的受力机理和特点。运用PLAXIS分析基坑开挖周边土体变形和临近桥墩的侧移情况,定量给出桩锚-土钉复合支护的经济性分析。工程实测数据表明,桩锚-土钉复合支护可有效控制基坑侧向变形,实现对临近桥墩桩基础的保护。相对于传统围护-内支撑形式,桩锚-土钉复合支护造价低廉、可节省大量工程投资,经济效益显著。     

铁路建设项目经济评价信息系统的设计与应用

作者通过对铁路建设项目经济评价业务特点的分析,提出了利用计算机辅助经济评价的设计思想,并对运量预测、运营成本计算的算法作了详细讨论。     

抓住时机 大力开发水泥路面机械

本文从水泥路面的重要性出发,介绍了水泥路面施工工艺流程与机械化施工成套设备的初步规划,提出了配套与配合机械产品开发设想,并就其市场需求与产品社会、经济效益进行了初步分析。     

影响施工机械经济寿命计算因素的探讨

施工机械经济寿命的计算，是施工机械更新决策中确定其最佳更新期的一个重要方法．本文针对影响施工机械经济寿命计算准确性的有关因素，分析其产生的原因，提出了利用率修正系数、币值变动修正系数和无形磨损引起的相对经济寿命的三种修正方法，并运用实例进行了计算、分析。     

Modeling the Effects of Population Density on Prospect Theory-Based Travel Mode-Choice Equilibrium

In conventional transportation planning models, it was always assumed that the population density is given and fixed in the study areas. Therefore, the effects of population density on travel choice have not been explicitly incorporated into these existing models for long-term transportation planning. Meanwhile, travel choice models in previous studies are usually developed by using discrete choice theories or user equilibrium principle. Thus, many significant characteristics of travelers’ behaviors, such as risk preference and learning process over time, cannot be considered in these conventional models. This article proposes a convex prospect theory-based model to investigate the effects of population density on the travelers’ mode-choice behavior under an advanced transportation information system (ATIS) in a multimodal transportation corridor. It is shown that population density is closely co-related to the modal split results and dependent on the performance of the railway mode in the study corridor. The park-and-ride mode may not be suitable for areas with high population density. This article also investigates the travelers’ reference points on the generalized travel costs by modes. A numerical example is given to illustrate the properties of the proposed model together with some insightful findings.     

中巴喀喇昆仑公路冰川灾害

中巴公路穿越西喀喇昆仑-喜马拉雅山系的冰缘地带,沿线冰川活跃,冰川消融与进退等引发各类地质灾害,严重损毁公路,危及公路安全.中巴公路灾害防治是中巴公路改扩建工程的目标,科学防灾减灾需要掌握中巴公路沿线冰川及冰川灾害的形成及发展规律.通过野外调查、定点观测、文献检索与遥感解译等研究手段发现,独特的地形地貌、丰沛的夏季降雪、险峻的地形落差、山地气候波动等环境因素孕育大量跃动型冰川,具有长期萎缩与间歇跃动、同期不同步、夏季累积型和悬冰川的活动特征.中巴公路沿线可区分为四大活动性冰川群,洪扎河谷(Hunza River)一带的帕苏幕士塔格山冰川群(Pasu Mustaghs)最为活跃.中巴公路冰川灾害可分为冰川灾害与冰川地质灾害两大类别,10个类型.其中,冰湖溃决、冰川泥石流的治理是工程上主要面临的防治问题.     

Assessing the financial value of real-time energy trading services for privately owned non-commercial electric vehicles

Real-time energy trading services for privately owned non-commercial electric vehicles are characterized by an e-vehicle provider, by a provider of energy trading skills and technology, and by the fact that the latter manages (dis-)charging of the e-vehicle of the former with real-time energy prices. We conduct a simulation study to present a comprehensive assessment of the financial value of such services. Such an assessment is required in order to provide policymakers with guidance on if and how real-time trading services can serve as a tool to incentivize e-vehicle ownership. We propose a fully reproducible simulation model of the value creation process of real-time trading services, and use the model to assess services with a range of e-vehicle provider characteristics as well as with a range of technology setups. Our empirical results show that all considered real-time trading services are able to create significant energy cost savings, and that overall cost savings strongly depend on technology characteristics, surcharge rate, as well as on the e-vehicle provider's commute, household size, and office hours. We show that services including solar energy generation have the largest economic potential but do not necessarily maximize renewable energy deployment with residential households. We conclude with recommendations for policymakers on how to tap the full economic potential of real-time trading services for stimulating the adoption of e-vehicles.     

沥青路面就地冷再生技术在国道101线凌源段中修工程中的应用

结合国道101线凌源段中修工程,介绍了就地冷再生各种材料技术指标、施工工艺、使用性能及经济效益。     

浅谈就地热再生施工技术

介绍了路面就地热再生施工工艺,结合工程实例进行了经济效益分析。     

Economic impact of a supply change in mass transit in urban areas: A Canadian example

This paper aims at estimating the economic impact of a supply change in the bus transit service in a Canadian city of medium size. By using a quasi-experiment approach and a difference-in-differences (DID) estimator, it evaluates the impact of the introduction of a rapid bus transit (RBT) in Quebec City (Canada) through a spatio-temporal analysis of house price variations. The hedonic price model shows that the new service generates an increase in house price ranging from 6.9% to 2.9%, for those properties located close to the service corridor where the population is quite dense and where the service was offered initially. Using sales transaction data and municipal assessment records from 1997, the effect on price is translated into an economic impact for the whole region. The paper shows that the improvement in public transit supply generates, for Quebec City, a significant fiscal impact estimated to $6 M and a plus-value for properties owners close to $35 M over 12 years. Finally, the implications of this kind of analysis for urban planning and development are discussed.