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基于沉降率的填石路基压实质量控制标准 总被引:1,自引:0,他引:1
为了提高填石路基的强度和稳定度,避免不均匀变形对路基的不利影响,应用表面沉降法,研究了填石路基沉降率、密度、空隙率之间的关系。发现对于填石路基,上路堤单层摊铺厚度应控制在40 cm以内,沉降率应不超过3%:下路堤单层摊铺厚度应控制在60 cm以内,沉降率应控制在3%~5%之间。结果表明:以沉降率为指标的路基压实标准能够有效控制填石路基的压实质量。 相似文献
995.
分析了5年以上的陈化转炉钢渣的化学成分、力学性能以及稳定性能;研究了水胶比、集浆比以及钢渣粒径对透水混凝土强度和透水性能的影响.研究结果表明:集浆比、粒径大小是影响透水混凝土抗压强度和透水系数的关键因素;水胶比对钢渣透水混凝土的透水系数影较大,对28 d抗压强度影响不大. 相似文献
996.
随着港口现代化与船舶大型化的发展,沿海集装箱港区的泊位装卸效率也在迅速提高,单线航道利用率也受到了影响。基于计算机仿真技术,建立沿海集装箱港区船舶进出港作业系统仿真模型,着重研究泊位装卸效率对单线航道利用率的影响规律,为港口规划和建设决策提供参考。研究结果表明:提升泊位装卸效率可提高单线航道利用率,港区在提升泊位装卸效率来增加港口通过能力的同时,要兼顾其对航道利用率的影响,否则将会导致航道利用率过高,造成航道拥堵,降低航道服务水平等级。对于实例中的港区规模,建议装卸效率提升幅度不宜超过13%。 相似文献
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Xinkai WuHenry X. Liu Nikolas Geroliminis 《Transportation Research Part B: Methodological》2011,45(1):255-266
For uninterrupted traffic flow, it is well-known that the fundamental diagram (FD) describes the relationship between traffic flow and density under steady state. For interrupted traffic flow on a signalized road, it has been recognized that the arterial fundamental diagram (AFD) is significantly affected by signal operations. But little research up to date has discussed in detail how signal operations impact the AFD. In this paper, based upon empirical observations from high-resolution event-based traffic signal data collected from a major arterial in the Twin Cities area, we study the impacts of g/C ratio, signal coordination, and turning movements on the cycle-based AFD, which describes the relationship between traffic flow and occupancy in a signal cycle. By microscopically investigating individual vehicle trajectories from event-based data, we demonstrate that not only g/C ratio constrains the capacity of a signalized approach, poor signal coordination and turning movements from upstream intersections also have significant impact on the capacity. We show that an arterial link may not be congested even with high occupancy values. Such high values could result from queue build-up during red light that occupies the detector, i.e. the Queue-Over-Detector (QOD) phenomenon discussed in this paper. More importantly, by removing the impact of QOD, a stable form of AFD is revealed, and one can use that to identify three different regimes including under-saturation, saturation, and over-saturation with queue spillovers. We believe the stable form of AFD is of great importance for traffic signal control because of its ability to identify traffic states on a signal link. 相似文献
998.
针对卫星信号功率微弱易受干扰的问题,以GPS接收机失锁时的干信比门限作为接收机是否被干扰而失锁的判别标准,研究伪卫星增强信号功率提高接收机接收卫星信号抗干扰能问题。 相似文献
999.
Zhenhua Xu Jianguo Huang Hai Huang Qunfei Zhang College of Marine Engineering Northwestern Polytechnical University Xi’an China 《船舶与海洋工程学报》2011,10(3):358-363
In order to solve the distributed detection fusion problem of underwater target detection, when the signal to noise ratio (SNR) of the acoustic channel is low, a new strategy for united detection fusion and communication using multiple sensors was proposed. The performance of detection fusion was studied and compared based on the Neyman-Pearson principle when the binary phase shift keying (BPSK) and on-off keying (OOK) modes were used by the local sensors. The comparative simulation and analysis between the optimal likelihood ratio test and the proposed strategy was completed, and both the theoretical analysis and simulation indicate that using the proposed new strategy could improve the detection performance effectively. In theory, the proposed strategy of united detection fusion and communication is of great significance to the establishment of an underwater target detection system. 相似文献
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