特大断面隧道施工工序优化研究

本文依托重庆火凤山隧道工程的修建开展研究,通过数值模拟,分析了不同施工工序对各断面形状的影响效果,并结合各断面形状所采用的施工工法,提出合理的施工工序.结果表明:(1)对于采用CD法施工的17 m特大断面段与21 m特大断面段而言,优化后的施工工序对围岩位移与塑性区的控制效果较为有限,但能有效改善开挖过程中初期支护应力的应力集中现象、降低应力值,且应力集中分布的位置有所差异.同时,通过优化施工工序能够减小支护结构左右侧应力分布不均匀程度,改善隧道开挖后支护结构的受力状态;(2)通过采用左右交互开挖的施工工序,24 m特大断面段与30 m特大断面段的围岩位移与支护结构应力均有所减小,同时对围岩的扰动也有所下降,但改善效果不及CD法明显.整体而言,优化后的施工工序对24 m特大断面段与30 m特大断面段隧道开挖较为有利,建议采用优化后的施工工序进行施工.     

公路隧道施工监理的措施优化

公路隧道工程施工难度大,施工工艺复杂、工期长,且对施工质量有较高的要求,为保证公路隧道工程施工保质保量地完成,文章从监理的角度出发,对公路隧道施工监理中的质量控制问题进行分析,并提出一些公路隧道施工监理措施优化方法,以供参考。     

计算机辅助PERT网络计划技术在施工中的应用

在分析国内外网络计划技术发展的基础上,总结介绍计算机辅助PERT网络技术的特点和优势,指出计算机辅助PERT网络技术的应用是施工企业降低成本、提高项目计划管理水平的有效方法.     

从时间上优化交通资源

<正>优化交通资源配置是交通运输发展的永恒主题。优化交通资源配置的方式从客观上分为空间和时间两个方面。在我国快速工业化和城市化发展阶段,从空间上优化交通资源似乎更受重视。为了缓解交通拥堵,道路越修越多,越修越宽,然而道路的增长似乎永远赶不上交通需求的增长,伴随着交通基础设施快速增长的却是出行效率的下降。     

转型实践：以城际公交优化网络

近年来,湖北宜昌交运集团股份有限公司（以下简称“宜昌交运“）在谋求转型升级、创新发展过程中,将集约发展作为核心、提升服务作为关键。为充分发挥了公路客运的比较优势,实现与高铁、航空紧密衔接,无缝对接,企业加强了对区域资源整合,加大资金、科技、劳动的投入,推进公路客运区域网络的构建。     

公路隧道软弱围岩施工方法的探讨

文章根据当前软弱围岩中公路隧道的施工方法和施工特点,采用数值分析的方法,对台阶法、CD法、CRD法的施工力学特征和存在的问题进行了分析,并对各种施工方法进行了比较,提出了应用三种施工方法的建议。     

带时间窗的混和车辆路径问题的优化算法研究

文章针对带时间窗约束的混合车辆路径问题的特点,建立了带时间窗的混合车辆路径问题的数学模型,并设计了变邻域禁忌搜索算法对该问题进行求解。通过标准算例测试及与现有文献计算结果的比较,验证了该算法的有效性。     

天山胜利特长公路隧道施工方法探讨

天山胜利隧道属特长、高寒、高海拔、高地应力公路隧道,为全线控制性工程,采用传统的钻爆法施工很难满足施工安全、工期、环保等要求。基于此,文章通过对前期拟定的4种施工方案进行工期、经济性、安全和质量管控等方面的对比分析,最终确定主洞采用钻爆法+平行中导洞采用TBM法的三洞方案,达到了经济合理、安全可靠、缩短工期的目的。     

大型枢纽机场公路集疏运网络规划方法研究

论文在分析大型枢纽机场集疏运体系规划特点的基础上,研究集疏运公路网络的功能分类和组织模式,以北京新机场为例,进行公路集疏运网络规划示例分析。     

超粘精罩面在公路沥青路面预防性养护的应用

预养护措施作为延长道路使用寿命、提升路用性能的重要手段,在我国当前的道路建设运营管理中有着很高的关注度。目前国内应用较多的预养护技术包括：微表处、沥青薄层罩面、雾封层等。该文通过对沥青薄层罩面这一养护工艺进行了改进,尝试设计出一种新型的沥青薄层罩面类型——超粘精罩面。对NovaPave超粘精罩面原材料的选择与混合料的设计,对混合料的高温稳定性和水稳定性进行验证。根据试验段铺筑的效果,总结出关键施工工序。在施工后进行摆值、构造深度与平整度的性能测试,验证了超粘精罩面可以明显改善路表的抗滑性能和行驶舒适度;进而通过与其他类型沥青薄层罩面相比,证明超粘精罩面具有较高的经济效益。     

公路施工项目成本管理的探讨

对公路工程项目管理成本控制的原则进行分析。结合在滨德高速公路的施工项目,提出了成本控制措施。     

农村公路的建设与设计

通过农村公路建设原则,提出了农村公路网建设要重实用、重排水、重防护的设计要点。     

Applicability of highway alignment optimization models

This paper presents an intelligent optimization tool that assists planners and designers in finding preferable highway alignments, connecting specified endpoints or zones. It integrates genetic algorithms with a geographic information system (GIS) for optimizing highway alignments and processes massive amounts of relevant data associated with highway design and alternative evaluation. To show the applicability of the proposed model to a real-world problem, two actual highway projects in the state of Maryland have been analyzed using the model. An extensive analysis of sensitivity to key model parameters is also conducted to describe the model capabilities. The analysis results show that the model can effectively optimize highway alignments in an area combining complex terrain and various types of natural and cultural land-use patterns, and provide detailed information of optimized alignments as a model output. It is also found that the alignments optimized by the model are quite similar to those obtained through conventional manual methods by a state agency, but the model can greatly reduce the time required for highway planning and design as well as produce lower cost solutions. Finally, the results confirm that all dominating and alignment-sensitive costs should be simultaneously evaluated in the alignment optimization process because many trade-off opportunities exist among those costs. The proposed model can greatly contribute to the productivity of highway planners as well as to the quality of the resulting infrastructure.     

公路施工项目的进度控制

分析了影响公路施工项目进度的因素,介绍进度计划的制定和实施,提出工程进度的控制措施。     

流态粉煤灰在公路建设中的运用

简要介绍了流态粉煤灰在高速公路中的运用,采用液态粉煤灰回填桥头台背技术,解决台背施工的难题,减轻建成通车后桥头跳车问题的出现。     

Multi-objective highway alignment optimization incorporating preference information

This paper presents a GIS-based multi-objective optimization model, particularly designed to aid highway engineers and planners in proposing competitive highway alignment alternatives when building a new highway or expanding an existing highway. The proposed model can effectively examine tradeoffs among various objectives that represent possibly conflicting interests of different stakeholders. A Hybrid Multi-Objective Genetic Algorithm, which utilizes designers’ knowledge about the preference of decision makers, is developed to search for a set of Pareto-optimal solutions with an acceptable level of diversity. Two case studies demonstrate the capability of the proposed approach in providing multiple trade-off solutions. The results indicate that the incorporation of preference information, even if preliminary in nature, has great potential to save computation time and improve the quality of the obtained Pareto-optimal set.     

对公路隧道施工监测的几点探讨

结合工程实例介绍了公路隧道施工监测的主要内容及其作用,并对施工监测中存在的一些问题进行了探讨,对提高公路隧道施工监控量测的质量具有一定的指导作用。     

Global optimization method for network design problem with stochastic user equilibrium

In this paper, we consider the continuous road network design problem with stochastic user equilibrium constraint that aims to optimize the network performance via road capacity expansion. The network flow pattern is subject to stochastic user equilibrium, specifically, the logit route choice model. The resulting formulation, a nonlinear nonconvex programming problem, is firstly transformed into a nonlinear program with only logarithmic functions as nonlinear terms, for which a tight linear programming relaxation is derived by using an outer-approximation technique. The linear programming relaxation is then embedded within a global optimization solution algorithm based on range reduction technique, and the proposed approach is proved to converge to a global optimum.     

A stochastic optimization model for transit network timetable design to mitigate the randomness of traveling time by adding slack time

Transit network timetabling aims at determining the departure time of each trip of all lines in order to facilitate passengers transferring either to or from a bus. In this paper, we consider a bus timetabling problem with stochastic travel times (BTP-STT). Slack time is added into timetable to mitigate the randomness in bus travel times. We then develop a stochastic integer programming model for the BTP-STT to minimize the total waiting time cost for three types of passengers (i.e., transferring passengers, boarding passengers and through passengers). The mathematical properties of the model are characterized. Due to its computational complexity, a genetic algorithm with local search (GALS) is designed to solve our proposed model (OPM). The numerical results based on a small bus network show that the timetable obtained from OPM reduces the total waiting time cost by an average of 9.5%, when it is tested in different scenarios. OPM is relatively effective if the ratio of the number of through passengers to the number of transferring passengers is not larger than a threshold (e.g., 10 in our case). In addition, we test different scale instances randomly generated in a practical setting to further verify the effectiveness of OPM and GALS. We also find that adding slack time into timetable greatly benefits transferring passengers by reducing the rate of transferring failure.     

公路运输枢纽站场投融资模式

与公路建设相比,作为公路交通基础设施重要组成部分的枢纽站场建设却相对滞后,使公路运输组织化程度难以提高,一定程度上影响了公路运输综合效益的发挥.因此,创新公路站场投融资体制,拓展融资渠道,优化投资结构,满足公路运输站场建设的资金需求,成为"十一五"亟待解决的课题.