大体积混凝土施工技术

该文对大体积混凝土施工应采取的技术措施作了较详细的介绍,并以汕头市游泳跳水馆工程底板大体积混凝土施工作为工程实例,从施工特点、施工技术措施和实施效果加以分析。     

丹东市水土流失防治措施研究

该文针对辽宁丹东水保生态环境不断恶化的情况,分析了造成水土流失加剧的原因,并通过丹东市的治理实践,提出了防治措施和科学的治理模式。     

郑州市城市交通体系中非机动车交通的现状与前景

作为地处黄河中下游流域的平原城市,非机动车交通在21世纪的郑州市交通体系中仍然占据着重要的地位。该文就非机动车交通在郑州市交通体系中的现状及前景进行了论述,探讨适合于郑州市的非机动车交通发展方向。     

门形刚架人行天桥的设计及优化

在人行天桥的设计中,采用门形刚架结构代替传统的简支钢箱梁,可以显著提高结构竖向振动基频,从而减小梁高,提升景观效果。该文以天津市南京路人行天桥改建工程为背景,论述了结构选型的过程。为了利用旧桥偏弱的桩基础和承台,设计中对多种优化思路进行了试算,最终确定为两铰门形刚架结构形式。墩梁固结处则采用柱穿梁的方法保证了主梁和墩柱的有效连接。     

浅议水平定向钻施工技术及其在杉杉河截污工程中的应用

杉杉河截污工程是宁波市中心城区内河整治工程之一。该文介绍了工程中非开挖施工埋设污水管技术及施工方案实施过程。     

全地下式雨水泵站及调蓄池在世博会园区中的应用

为解决初期雨水直排水体所带来的水环境污染问题,同时为合理利用地下空间并尽量减小泵站和调蓄池对周边环境的影响,世博园区后滩雨水泵站及调蓄池设计为全地下式合建排水构筑物。该文详细介绍了该工程的设计规模和调蓄池的布置、设计计算及运行模式等,并对工程特点和注意事项进行了总结,在类似工程中可结合其工程自身特点予以应用。     

济南市“7.18”特大暴雨洪水灾害成因分析及对策

2007年7月18日,济南市遭受了特大暴雨洪水灾害袭击,造成了严重损失。该文重点分析了"7.18"洪灾发生的主要原因,提出了完善济南市城市防洪体系的主要对策。     

Analysis of taxi demand and supply in New York City: implications of recent taxi regulations

This paper investigates temporal and weather-related variation in taxi trips in New York City. A taxi trip data-set with 147 million records covering 10 months of activity is used. It is shown that there are substantial variations in ridership, taxi supply, trip distance, and pickup frequency for different time periods and weather conditions. These variations, in turn, cause variations in driver revenues which is one of the main measures of taxi supply–demand equilibrium. The findings are then used to discuss the anticipated impacts of two recently enacted taxi regulation changes: the first fare increase since 2006 and the E-Hail pilot program which allows taxi hailing with smart phone applications. The fare increase is estimated to cause varying levels of revenue increase for different time periods. E-Hail apps are not expected to offer considerable improvements at all times, but rather when both adequate taxi supply and demand occur simultaneously.     

Telecommuting and urban sprawl

This study examines what happens to city size when telecommuting occurs. It assumes that more telecommuting occurs when telecommuters’ labor cost share increases and/or workers adopt a more favorable attitude toward working from home. The study shows that telecommuting produces opposing forces that regulate the city size, one centralizing and the other decentralizing urban activities. These forces are examined in a city where workers and firms are given the option to freely mix working at the office and at home, and the city’s land use is endogenously determined. A rise in the productivity of an economy due to telecommunications technology could work to centralize urban activities, while urban contraction can occur with a fixed city population.     

向家坝日调节运行对长江叙渝段航道维护影响研究

金沙江最下游梯级向家坝水电站,因其装机容量大,发电运行期间非恒定流造成坝下水位日变幅及小时变幅较大,会对长江叙渝段航道维护造成严重影响。基于长河段非恒定流数学模型,研究向家坝水电站日调节运行后长江上游非恒定流传播特性,分析日调节运行对航道维护的影响,提出相应航道维护管理对策。