共查询到18条相似文献,搜索用时 78 毫秒
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以现浇梁专用混凝土布料机为例,选择大长度悬臂梁为对象,运用Simulation有限元计算软件,对3种工况进行计算,并分析计算结果,对结构进行优化。 相似文献
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介绍了影响混凝土布料机功能可靠性发挥的因素,并对各影响因素的相互关系进行了分析,得出了影响布料机功能可靠性因素的统计学规律,从而提高布料机的生产效率,在今后的水电站建设中发挥更大的作用. 相似文献
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J. L. Ponz‐Tienda A. Salcedo‐Bernal Eugenio Pellicer 《Computer-Aided Civil and Infrastructure Engineering》2017,32(6):474-498
The efficient use of resources is a key factor to minimize the cost while meeting time deadlines and quality requirements; this is especially important in construction projects where field operations make fluctuations of resources unproductive and costly. Resource Leveling Problems (RLP) aim to sequence the construction activities that maximize the resource consumption efficiency over time, minimizing the variability. Exact algorithms for the RLP have been proposed throughout the years to offer optimal solutions; however, these problems require a vast computational capability (“combinatorial explosion”) that makes them unpractical. Therefore, alternative heuristic and metaheuristic algorithms have been suggested in the literature to find local optimal solutions, using different libraries to benchmark optimal values; for example, the Project Scheduling Problem LIBrary for minimal lags is still open to be solved to optimality for RLP. To partially fill this gap, the authors propose a Parallel Branch and Bound algorithm for the RLP with minimal lags to solve the RLP with an acceptable computational effort. This way, this research contributes to the body of knowledge of construction project scheduling providing the optimums of 50 problems for the RLP with minimal lags for the first time, allowing future contributors to benchmark their heuristics methods against exact results by obtaining the distance of their solution to the optimal values. Furthermore, for practitioners, the time required to solve this kind of problem is reasonable and practical, considering that unbalanced resources can risk the goals of the construction project. 相似文献
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为准确快速确定混凝土热力学参数中难以确定的绝热温升、导热系数、表面放热系数及反应速度,以云南普立大桥散索鞍支墩基础大体积混凝土施工实测温度为基础,采用遗传算法进行混凝土热力学参数的反演分析,并根据反演参数建立三维有限元模型预测后续混凝土施工中的温度场,然后通过混凝土内部实测温度及应力验证预测结果。最后依据预测结果,在混凝土浇筑早期采用表面降温,内部布设冷却水管的措施有效减小了内外温差并防止了裂缝产生。结果表明:混凝土内部温度达到峰值时表面拉应力最大值为1.5 MPa,出现表面裂缝的可能性较小;混凝土浇筑3 d后,抗裂指数都在1.5以上,一般不会产生裂缝;基于反演参数的温度场计算值与实测值吻合良好。 相似文献
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通过在混凝土中双掺玄武岩纤维和粉煤灰,设计4种试验方案配制高性能混凝土,测试了纤维掺量改变混凝土抗碳化性能的法则,基于RCM法研究了碳化3 d、7d、14 d和28 d四个龄期条件下,氯离子扩散的变化规律.研究表明:掺加纤维会增强混凝土抗碳化能力,当纤维体积含量是1.6 kg/m3时,混凝土抗碳化能力最强;氯离子扩散系数随着混凝土养护时间的延长而变小,早期速度变小快,后期减小慢,其机理是碳化产生CaC03堆积在混凝土中,充填了混凝土的孔隙,使混凝土的耐久性能得到改善,为在工程中应用提供参考. 相似文献
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某城市立交改建需凿除部分箱梁翼缘与新桥结合,由于横粱配有横向预应力钢束,在凿除翼缘混凝土前应明确横粱处预应力作用范围以指导施工安全.文章采用ANSYS有限元程序建立端、中横梁局部实体模型,确定了横向预应力影响范围及应力分布规律,并提出建议保留区域,为该类桥梁拓宽改造提供设计依据. 相似文献