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991.
一干河特大桥位于溧水至马鞍山高速公路江苏段,主桥为三跨大跨度预应力混凝土变截面连续箱梁。介绍了主桥的设计要点,包括箱梁构造、内力计算分析、预应力钢束布置等内容。该桥主桥设计要点可为其他同类桥型设计提供参考。 相似文献
992.
993.
In this paper, numerical analyses of the thermal performance of an indirect evaporative air cooler incorporating a M-cycle cross-flow heat exchanger has been carried out. The numerical model was established from solving the coupled governing equations for heat and mass transfer between the product and working air, using the finite-element method. The model was developed using the EES (Engineering Equation Solver) environment and validated by published experimental data. Correlation between the cooling (wet-bulb) effectiveness, system COP and a number of air flow/exchanger parameters was developed. It is found that lower channel air velocity, lower inlet air relative humidity, and higher working-to-product air ratio yielded higher cooling effectiveness. The recommended average air velocities in dry and wet channels should not be greater than 1.77 m/s and 0.7 m/s, respectively. The optimum flow ratio of working-to-product air for this cooler is 50%. The channel geometric sizes, i.e. channel length and height, also impose significant impact to system performance. Longer channel length and smaller channel height contribute to increase of the system cooling effectiveness but lead to reduced system COP. The recommend channel height is 4 mm and the dimensionless channel length, i.e., ratio of the channel length to height, should be in the range 100 to 300. Numerical study results indicated that this new type of M-cycle heat and mass exchanger can achieve 16.7% higher cooling effectiveness compared with the conventional cross-flow heat and mass exchanger for the indirect evaporative cooler. The model of this kind is new and not yet reported in literatures. The results of the study help with design and performance analyses of such a new type of indirect evaporative air cooler, and in further, help increasing market rating of the technology within building air conditioning sector, which is currently dominated by the conventional compression refrigeration technology. 相似文献
994.
通过对蚌埠市淮河路地下街设计项目的背景与概况、设计思路与设计原则与手法的总结与分析,探索了在城市核心区的地下街规划过程中,如何在藉由地上地下一体化的设计方式,确保地下街的空间环境、人流、景观与城市活动的基础上,利用地下街的开发,让城市地下空间的开发能够扩大城市便利性、重新定义场所精神、发掘土地潜力、结合低碳技术、人防工程与城市防灾,谋求地上地下商业的共同发展,并创造出城市核心区中舒适与宜人的立体化公共空间体系。 相似文献
995.
针对某大断面公路盾构隧道火灾烟气控制工程实际,为了优化设计公路隧道集中排烟模式下排烟阀结构参数,采用火灾动力学模拟软件FDS构建了隧道数值模型,并根据公路隧道的通行车辆种类、火灾类型和火灾规模,选择了隧道火灾典型场景,设计了集中排烟模式下单向及双向排烟时相应的火灾工况,通过提取隧道顶隔板下方温度场、行车道2 m高处能见度以及排烟阀流速等数据,分析了双向排烟时特定排烟阀面积下不同排烟阀结构形状对隧道火灾排烟效果的影响,进而探讨了单向排烟方式下不同排烟阀面积时的隧道火灾排烟效果。在此基础上,获得了隧道集中排烟模式下合理的排烟阀面积、排烟阀结构形状等设计参数。 相似文献
996.
997.
This paper presents tensile test results of CFRP strengthened steel plates (CS) after wet and dry corrosion. The number of cycle times and strengthened schemes were investigated. The results showed that the CS specimens, subjected to wet–dry corrosion, behaved in a more brittle manner and appeared massive CFRP and adhesive rupturing coincided with the failure. As the wet–dry cycle increasing, the yield strength and ultimate strength of CS strengthened specimens decreased significantly, while the stiffness before and beyond yield strength degraded slightly. Furthermore, the yield strength and ultimate strength of double-sided specimens subjected to wet–dry cycles were higher than those of one-sided specimens. Finally, analytical formulas considering wet–dry corrosion were proposed to predict elastic modulus, yield strength, tangent modulus, ultimate strength of CS specimens subjected to wet–dry cycles, respectively. The calculated results were in good agreement with experimental values. 相似文献
998.
Xilin Lu Cong Chen Yun Chen Jiazeng Shan 《The Structural Design of Tall and Special Buildings》2016,25(17):947-966
An innovative structural component, replaceable coupling beam (RCB), was developed and used in reinforced concrete (RC) structures to enhance the structural performance. During strong earthquakes, damage may occur in replaceable devices to prevent severe damage in primary structural parts, and the damaged devices could be replaced after earthquake. This paper introduces the theory and design method as well as the application of RCBs to RC structures. First, a practical design procedure for RCBs was proposed. Then, cyclic static tests of the RC shear walls with and without RCBs were conducted. At last, a systematical RCB application to RC structure was introduced, and dynamic analysis for the entire structures was performed. The results indicate that RCB has good seismic performance by concentrating damage in the replaceable devices, while the global responses of the structures with and without RCBs changed slightly. Dynamic properties of the real structure were measured through the ambient vibration test, and the test results further validated the dynamic analysis to some extent. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
999.
1000.
水电工程施工监理大纲是监理单位承诺书,反映了监理单位的技术和管理水平等综合实力,其编制质量是中标签约的决定因素之一。文章总结了水电工程施工监理大纲编制质量管理的经验,论述了施工监理大纲的编制内容、方法。 相似文献