干熄焦锅炉炉管失效机理分析

通过对干熄焦锅炉炉管及腐蚀产物开展系统研究，提出炉管失效原因为氧化/硫腐蚀＋高温粉尘冲刷。长寿命炉管仅耐磨层发生了较为严重的氧化及硫腐蚀，而近基体层发生了轻微氧化及硫腐蚀，基体只发生了轻微氧化；短寿命炉管耐磨层、近基体层以及基体裂纹内均发生了较为严重的氧化及硫腐蚀，且存在珠光体球化、内表面产生全脱碳层等缺陷。推测短寿命炉管存在超温现象，而超温可加剧氧化及硫腐蚀反应。此外，短寿命炉管遭受了较为严重的高温粉尘冲刷，不仅可造成炉管减薄，还会导致炉管表面温度升高。因此，减少循环气体中粉尘量尤其是大颗粒，可有效减弱冲刷以及控制炉管表面温度，是提高炉管使用寿命的关键。     

双向刮板输送机的技术改造

由于双向刮板输送机存在种种弊端，远不能满足生产要求。为适应井下生产，利用现有空间，将刮板输送机及附属设施改为胶带输送机，使用后效果良好。     

严重垮冒主溜井新型加固方法的研究与实践

针对程潮铁矿2号主溜井垮落后的稳定状况,提出了“托斗”结构为主要支护形式的总体返修加固方案,实践证明,该方案不仅工期甜酸、投资和,而且溜井返修后稳定性良好,为严重垮冒主溜井结构的恢复提供 了新方法。     

阳泉矿区部分建（构）筑物破坏的原因分析和对策

本文介绍了阳泉矿区部分建(构)筑物由于受地基不均匀沉降、湿陷、潜蚀、管涌、地面塌陷等影响,导致建(构)筑物破坏的情况,在分析破坏原因的基础上,提出了相应的对策。     

Management of bridges with shallow foundations exposed to local scour

Abstract

The Serbian road network includes a large portion of bridges with shallow foundations vulnerable to local scour as tragically demonstrated during the extreme flooding in May 2014. Currently, the bridge management procedures in Serbia and worldwide do not comprehensively account for a risk of bridge failure due to flooding and fail to provide sufficient information for the decision-making. Thus, a novel methodology for quantitative vulnerability assessment is suggested as a tool to identify the most vulnerable bridges in a network. Herein, the essential task is evaluation of the conditional probability of a bridge failure due to local scour in a flooding event of a certain magnitude. To apply this approach on a network level, there is a dire need to establish precise practice-ready guidelines on an optimal set of information to be used and/or collected in situ, which is discussed on an example of the Serbian bridge database. The vulnerability of a bridge to local scour may be used as a comprehensive indicator of a bridge performance in a flooding event. For a network level, the vulnerability maps with respect to flooding of different magnitudes will give road operators crucial information to apply adequate quality control plans to vulnerable bridges.     

桥渡冲刷计算方法分析

对各类冲刷公式建立的依据以及公式的适用条件进行了分析,介绍了公式发展历史,并提出现在应用这些公式所面临的问题以及解决方法,为桥下河槽冲刷的进一步研究提供了理论基础。     

冲刷作用下层状横观各向同性土中群桩水平振动响应

采用有限元(FEM)与间接边界元(BEM)耦合法,求解冲刷作用下层状横观各向同性地基中高承台群桩的水平振动响应。采用三节点梁单元对群桩进行离散;然后,基于层状横观地基频域内的解答,以及考虑桩–桩相互作用,建立了地基积分方程;再通过对积分方程离散和数值求解,得到地基的柔度矩阵;根据桩土之间的协调条件,推导出群桩与地基共同作用的方程;通过引入各基桩桩顶的边界条件,获得共同作用方程的解答。最后,通过相关数值算例,验证本文理论及结果的正确性,并讨论冲刷深度对群桩水平振动响应的影响。     

沙漠砂贫混凝土在变电站塌陷治理中的应用

变电站内地下电缆沟槽纵横交错,而电缆沟本身空间狭小,这导致传统的回填方法无法夯实,且传统的回填土抗冲刷能力差,导致后期出现了不均匀沉降和因冲刷而诱发的塌陷。针对这种沉降和塌陷,以月牙湖330kV变电站塌陷治理为依托,提出一种有针对性的施工方法,也就是通过制备可以自密实的沙漠砂贫混凝土浆液,对这些狭小坑道进行灌注,解决了无法夯实的问题,且沙漠砂贫混凝土浆液固化后具有较强的抗冲刷能力,避免了后期使用中的冲刷塌陷,减小了维护频率。     

新型地锚扶壁式泥石流格栅坝基础冲刷计算方法研究

泥石流格栅坝工程安全稳定的关键是基础,相比外露结构的计算,基础遭冲刷掏空的问题更值得引起重视。在提出新型地锚扶壁式泥石流格栅坝的基础上,将格栅坝基础冲刷分为初期和中后期两个阶段,初期冲刷主要以坡面冲刷为主,中后期冲刷主要考虑冲坑的变化发展。基于能量法,推导了格栅坝基础冲刷深度的计算公式,通过算例分析了不同流深下的冲刷深度,并与其它公式的计算结果做了对比。结果表明:推导公式计算的冲刷深度比其它公式计算的结果都大,初期冲刷的影响在设计中应当予以重视。     

Hybrid intelligent inference model for enhancing prediction accuracy of scour depth around bridge piers

Bridge-pier scouring is a main cause of bridge failures. Thus, accurately predicting the scour depth around bridge piers is critical, both to specify adequate depths for new bridge foundations and to assess/monitor the safety of existing bridges. This study proposes a novel artificial intelligence (AI) model, the intelligent fuzzy radial basis function neural network inference model (IFRIM), to estimate future scour depth around bridge piers. IFRIM is a hybrid of the radial basis function neural network (RBFNN), fuzzy logic (FL), and the artificial bee Cclony (ABC) algorithm. In the IFRIM, FL is used to handle the uncertainties in input information, RBFNN is used to handle the fuzzy input–output mapping relationships, and the ABC search engine employs optimisation to identify the most suitable tuning parameters for RBFNN and FL based on minimal error estimation. A 10-fold cross-validation method finds that the IFRIM model achieves at least 21% and 14.5% reductions in root mean square error and mean absolute error values, respectively, compared with other AI techniques. Study results support the IFRIM as a promising new tool for civil engineers to predict future scour depth around bridge piers.