钉形双向搅拌桩在软土地基处理中的应用

钉形水泥土双向搅拌桩（钉形搅拌桩）是在常规搅拌桩基础上对施工设备进行改进,具有双向旋喷、变径、复搅、深度大等特点。结合临沂至连云港高速公路沿海软土地基的实际情况,详细介绍了施工步骤、技术参数及成桩效果。最后经过经济、强度等对比分析,说明了钉形双向搅拌桩的优越性。     

车道拥挤收费与信号控制组合优化模型研究

针对设有公交专用车道的城市道路,在交通过饱和状态下,为了提高道路通行能力,允许私家车以收费模式驶入公交专用车道,以缓解交通拥堵,建立了基于拥挤收费的交通信号控制模型.模型分别计算了公交专用车道和常规车道的行程时间及相关联交叉口的总体排队延误,另外对公交专用车道设置了临界密度.该模型在保证公交专用车道交通服务水平的前提下使所有车道的路段行程时间及路口排队时间最短,最后利用遗传算法和VISSIM仿真相结合对模型进行了求解.结果显示了车道拥挤收费和信号控制组合优化模型的有效性,降低了车辆排队延误.     

公交专用道运营效果评价方法研究

本文采用数据驱动的方法对公交专用道的运营效果评价研究进行了深入探析,通过实例分析,运用层次分析法,选取重庆长江大桥段公交专用道进行公交运营效果评价研究,根据实际情况,选取公交、社会车辆、社会经济等三个系统建立评价指标体系,构建评价分析模型。最后,对不同情境下的公交专用道运营效果展开对比分析,论证公交专用道的实施所带来的不同效益,从而为公交专用道发展研究起到一定的促进作用。     

港区道路调头车道设计研究

港口大型车辆比例较高,这些车辆调头时所需要的空间和时间也比小汽车要大,针对这些因素,进行了港区道路专门的调头车道设计。     

AES加密算法的密钥搜索量子线路设计

为验证量子搜索应用于分组密码密钥搜索的可行性,在分析AES算法计算流程和需要实现的计算模块的基础上,设计了一种AES算法密钥搜索的量子线路,包括密钥扩展KeyExpansion模块、量子加密模块和量子比较模块.其中,量子加密模块包含量子轮密钥加AddRoundKey、量子字节代换SubBytes、量子行移位ShiftRows和量子列混淆MixColumns.为了使辅助比特能被后续计算重用,采用回退计算方法去除量子纠缠,在实现量子加密模块时根据4个子模块的不同计算任务采取相应的回退计算策略,以节省计算时间和量子存储空间.研究结果表明:将量子搜索算法应用于分组密码的密钥穷举搜索攻击以达到二次方加速是可行的.     

龙山大跨连拱隧道设计与施工

龙山连拱隧道是为适应芜湖经济的快速增长,贯通芜湖经济开发区凤鸣湖大道而修建的城市六车道双连拱隧道。龙山双连拱隧道最大埋深13 m,是目前国内建成的跨度最大、埋深最小的六车道双连拱隧道。介绍了该隧道的设计及现场施工,对今后类似工程提供一些借鉴经验。     

Evaluation of exclusive bus lanes in a bi-modal degradable road network

In this paper, we proposed an evaluation method of exclusive bus lanes (EBLs) in a bi-modal degradable road network with car and bus transit modes. Link travel time with and without EBLs for two modes is analyzed with link stochastic degradation. Furthermore, route general travel costs are formulated with the uncertainty of link travel time for both modes and the uncertainty of waiting time at a bus stop and in-vehicle congestion costs for the bus mode. The uncertainty of bus waiting time is considered to be relevant to the degradation of the front links of the bus line. A bi-modal user equilibrium model incorporating travelers’ risk adverse behavior is proposed for evaluating EBLs. Finally, two numerical examples are used to illustrate how the road degradation level, travelers’ risk aversion level and the front link’s correlation level with the uncertainty of the bus waiting time affect the results of the user equilibrium model with and without EBLs and how the road degradation level affects the optimal EBLs setting scheme. A paradox of EBLs setting is also illustrated where adding one exclusive bus lane may decrease share of bus.     

An analytical model to conduct a person-based evaluation of transit preferential treatments on signalized arterials

The complexities of urban transportation networks where multiple modes with different characteristics and needs travel in combination with constraints on space and funding make the sustainable management of these systems a challenge. In order to improve transit service, space (e.g., dedicated bus lanes) and time (e.g., transit signal priority strategies) Transit Preferential Treatments (TPT) are deployed to improve transit operations. The objective of this paper is to develop an analytical model that allows for a person-based evaluation of alternative TPTs when considered individually and in combination. In particular, the analytical model is developed to assess person delay and person discharge flow at any intersection that is part of a signalized arterial, where auto arrivals are in platoons. The performance of TPTs is evaluated using both the analytical model and through microsimulation tests on two intersections of San Pablo Avenue in Berkeley, CA. Space TPTs such as dedicated bus lanes and queue jumper lanes are beneficial in reducing bus person delay when provided in addition to the existing lanes; however, the effectiveness of time TPTs such as green extension depends on the level of auto demand in combination with signal settings. Changes in person discharge flow are not significant for any of the treatments tested with the exception of the bus lane substitution with and without green extension, which led to a significant decrease in person discharge flow. Increased bus frequency increases the effectiveness of transit signal priority in reducing total and bus person delay. The analytical model results produce ranking outcomes that are comparable with the microsimulation ones and therefore, the model may be used for a quantitative evaluation of TPTs without the need for data intensive and time consuming calibration efforts required for microsimulation models. The developed model can be used to guide infrastructure and investment decisions on where such TPTs should be implemented and under what conditions space TPTs should be combined with time TPTs to improve person mobility.     

Integrated optimization of transit priority operation at isolated intersections: A person-capacity-based approach

In this paper, a person-capacity-based optimization method for the integrated design of lane markings, exclusive bus lanes, and passive bus priority signal settings for isolated intersections is developed. Two traffic modes, passenger cars and buses, have been considered in a unified framework. Person capacity maximization has been used as an objective for the integrated optimization method. This problem has been formulated as a Binary Mixed Integer Linear Program (BMILP) that can be solved by a standard branch-and-bound routine. Variables including, allocation of lanes for different passenger car movements (e.g., left turn lanes or right turn lanes), exclusive bus lanes, and passive bus priority signal timings can be optimized simultaneously by the proposed model. A set of constraints have been set up to ensure feasibility and safety of the resulting optimal lane markings and signal settings. Numerical examples and simulation results have been provided to demonstrate the effectiveness of the proposed person-capacity-based optimization method. The results of extensive sensitivity analyses of the bus ratio, bus occupancy, and maximum degree of saturation of exclusive bus lanes have been presented to show the performance and applicable domain of the proposed model under different composition of inputs.