张家洲南港下浅区航道整治工程方案试验研究及整治效果分析

在分析长江下游张家洲水道南港(简称张南)下浅区演变特点的基础上,通过河工模型试验研究,确定了南港下浅区航道整治工程方案.该工程于2001-2003年实施后,浅区消失,航道条件明显改善,不仅达到现行航道维护尺度,而且满足<长江干线航道发展规划>中规划的近期航道建设标准.     

神背嘴滩整治方案与治理效果分析

在总结历史治理经验的基础上,通过模型试验研究了神背嘴滩的碍航特征及成滩原因。通过新开右槽、建整治建筑物等措施调整汊道分流比和束水攻沙,使航道尺度增大到2.7m×50m×560m,改善了枯水弯、浅、险的碍航问题,保证了航槽的稳定。整治方案可为山区河流急弯滩险治理提供借鉴。     

长江中下游五类典型河段航道整治工程经验总结

对长江中下游已实施航道整治工程的河段进行总结归类,提出了5类典型河段,即矶头控制下的弯曲放宽河段、鹅头分汊的弯曲河段、两反向弯道之间的过渡河段、微弯分汊河段和顺直分汊河段。针对这5类典型河段的航道整治,选取工程实例,从航道概况、整治方案以及工程效果等方面进行了论述。最后归纳总结了这5类河段航道整治在工程技术上所取得的成功经验,可为后续长江中下游类似河段的航道整治提供理论参考。     

穿浪双体船总体设计载荷研究

为了比较分析不同高速船规范的适用性,根据DNV、ABS、CCS和LR规范中关于高速双体船波浪载荷的评估方法,分别对一高速穿浪双体船进行了总体波浪设计载荷的评估。同时对该穿浪双体船进行了水池模型试验,包含规则波与不规则波的试验。试验对该双体船的纵垂向弯矩、横垂向弯矩、横向扭矩和纵摇有关扭矩进行了测量,分析了其传递函数和统计特性。根据对纵垂向弯矩、横垂向弯矩、横向扭矩和纵摇有关扭矩在规范与试验之间的比较分析表明,DNV规范中关于该穿浪双体船总体波浪设计载荷的评估与模型试验值最接近,CCS规范次之,ABS和LR规范中关于该穿浪双体船的总体波浪设计载荷的评估值较试验值大很多,尤其是横向波浪设计载荷的评估。通过对规范计算的总体波浪载荷与模型试验结果及其推断值的比较分析,进一步明确了现行规范对该双体船波浪设计载荷评估的适用性:采用DNV和CCS规范对该双体船进行结构设计是合理的;采用ABS和LR规范将偏于安全和保守。     

粉煤灰山砂路面砼的技术经济性研究

山砂替代砂应用于路面砼是一个不可回避的课题.本文以二级路宜———泸路的研究为依据,分析阐述了山砂路面砼不仅具有良好的工作特性、力学特性、干缩特性,而且具有显著的技术经济价值.     

The regulatory function in public-private partnerships for the provision of transport infrastructure

A wide range of contractual arrangements are increasingly being used by the public sector to materialise the delegation of transport infrastructure provision tasks to the private sector, over long periods of time. This paper addresses the issue of transport infrastructure regulation in the specific context of public-private settings. Starting by the discussion on the concept of Public-Private Partnership (PPP) it is stressed that, despite the different meanings that can be found in the literature, it is possible to define a PPP by using a core group of characteristics, such as the bundling of services and the transference of a relevant part of the risks to the private sector on a long term basis. Regarding the action of the regulator, we look at three dimensions of efficiency that are expected to be pursued at the strategic level of regulatory action. However, it is acknowledged that the regulatory function is in practice rather complex since it requires balancing a multiplicity of other objectives or goals, which may vary according to specific economic conditions. In the domain of pricing, the review carried out suggests that since “first best” assumptions are not met in the “real world” it hardly seems possible that the short run marginal cost pricing “canon” could be directly used to shape pricing policies. Consequently, when considering the application of the standard neoclassical marginal cost pricing approach it is pertinent to ask whether the second best solutions can lead to efficient outcomes that might be accepted by the stakeholders. Bundling construction and maintenance tasks into a single long term contract, which is a typical characteristic of “standard” PPPs, could theoretically bring cost benefits since it allows for the possible internalization of any positive externalities that may be generated during the whole project life cycle. The economic rationale for the bundling of construction/maintenance with financing services is that it enhances the likelihood of submission of realistic bids at the procurement stage. In addition, the chances of the contractor sticking to the agreed contractual terms, after contract award, are potentially increased given the higher exposure to financial risk.     

汉江福滩航道整治技术研究

受安康枢纽电站日调节的影响,坝下河段日内流量、水位变幅大;枯水流量很小,航道一年内约有20%左右的时间需要等水通航,碍航严重。对福滩滩性进行了分析,并提出了整治原则和方法,通过模型试验和工程实践取得了良好的效果。     

天然河流航道整治定级的理论计算方法

在编制航道发展规划时,首先应从自然条件角度论证航道资源的开发潜能,然后再根据社会经济不同发展时期的需要制定出各时期的航道建设方案。基于上述理念,文中以水力学、河流动力学等学科为理论基础,提出了一种天然河流航道整治定级的理论计算方法,能够反映天然河流经航道整治后可能达到的航道标准。经西江桂梧段航道基本资料的实例演算,表明该研究思路和方法合理可行,能使航道整治定级工作更趋科学合理。     

视频安全监控系统在浙赣线牵引变电所的应用

介绍了浙赣铁路牵引变电所的视频安全监控系统,分析了红外对射系统基本工作原理、监控系统中的嵌入式技术与高压缩编解码技术,针对视频安全监控系统的抗干扰性、施工工艺、应用情况和取得的效益进行了研究.     

大虎山至齐齐哈尔铁路增二线通辽枢纽作业分工探讨

针对通辽枢纽既有作业分工存在的问题 ,分析原因并提出新的作业分工方案。