UHPC 湿接缝浇筑在排水工程中的施工应用控制

预制拼装技术是水务结构施工工艺的重要发展趋势,接缝处理是当前预制拼装技术的关键技术难点。超高性能混凝土（UHPC）具有强度高、韧性大、耐久性好等技术优势,成为解决预制拼装结构接缝连接的有效途径。考虑到该技术在水务工程领域应用相对较少,根据实际工程开展了相关的研究。首先,针对UHPC湿接缝在排水结构的适用性问题、临时支撑的快速周转、高温与低温施工等难点进行了分析研究,通过全尺寸UHPC浇筑工艺试验,对施工参数进行了探索,并提出了高温与低温条件下浇筑策略。研究保证了UHPC湿接缝浇筑施工的顺利进行,有效提高了预制拼装施工效率,提升了湿接缝浇筑质量。     

Inconel 600复合钢板焊接接头结构的改进

焊接复合钢板时,对焊接接头的坡口形式有特殊要求,若坡口形式不当,当先焊接基层时,焊缝金属中可能熔入复层合金元素导致基层焊缝脆化;当先焊接复层时,焊缝金属中可能熔化基层使焊缝金属稀释,降低复层的耐蚀性。采用台阶式坡口形式。使基层和复层的焊接截然分开,避免第一道焊缝金属的互熔,是防止上述问题发生的最好措施。文中对原图样设计的焊接接头坡口形式存在的问题进行了分析,将改进后的台阶式坡口形式应用在设备的焊接上,取得了良好的效果。     

薄板焊接变形高精度预测方法的研究

采用固有应变方法预测焊接变形时,传统方法是把纵向收缩、横向收缩和角变形这三成分作为接头的固有变形来估算焊接变形。但是,由于薄板的刚度低,在纵向方向上的弯曲变形也较明显,采用传统方法会影响薄板焊接变形的预测精度。为提高精度,文章对传统的方法进行了改进,开发了包括考虑纵向弯曲在内的四成分固有变形数值计算方法来预测薄板焊接变形。数值模拟结果表明:运用该方法预测薄板的焊接变形时,比传统的方法有更高的精度,而且预测结果与热弹塑性有限元的模拟结果十分吻合。     

Three Dimensional Numerical Simulation Study on the Tensile Test of the Embedded Components in Segment Joints of Deep Buried Storage and Drainage Shield Tunnels北大核心CSCD

The numerical simulation was carried out based on tensile test of the embedded components in segment joints of the deep buried storage and drainage shield-driven tunnel in Shanghai in order to study the numerical approach for mechanical analysis of segment joints of the tunnel. Using the concrete damage plasticity model and nonlinear springs, the 3D refined numerical model was established, in which the embedded components with complex geometries and the bond-slip behaviors between the concrete and bars were taken into consideration. Three kinds of embedded component models with different degrees of refinement were established and simply loaded. By comparing the calculation results and considering the spent time and the accuracy of calculation, the simplified form of the embedded components used in the overall model was determined. Nonlinear springs between anchor bars and concrete were set in the model in order to simulate the bond-slip behavior between them. In addition, two contrast models were also established using binding constraint and face-face contact constraint between concrete and anchor bars respectively. The three types of models were loaded in accordance with the test conditions. Comparing the results of the numerical calculation with the test results, it is shown that the "nonlinear spring model", which takes the bond-slip behavior into consideration, is more consistent with the test results than the "face to face contact model" and "binding model". And the model also reflects the failure mode very well. It indicates that the three dimensional refined modeling method used in this paper is applicable for similar tensile tests. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

盾构管片接头抗弯刚度影响因素研究

研究目的:推导盾构隧道管片接头抗弯刚度计算公式,研究不同影响因素作用下接头抗弯刚度的变化规律.研究结论:管片接头的接触面有效高度和接触面偏心距对管片接头抗弯刚度的影响显著,因此管片结构设计中,通过改变管片接头构造尺寸来调整管片接头刚度是一种有效的手段.     

浅谈公路桥梁伸缩缝施工质量控制措施

桥梁伸缩缝是桥梁上部构造的薄弱部位,直接承受车荷反复冲击作用,从选定产品施工工艺等方面,对伸缩缝施工提出几点技术建议。     

5900DWT沥青船开发和设计

5900DWT沥青船是一种全新的船型,设计过程中需要考虑高温、热传导损失、弹性联接等高温船的特点。该船型采用独立液货舱的特殊结构形式,并进行了有限元非线性校核,满足大部分油船的布置,其中管系布置较常规船型更为复杂。     

Ag-Cu-Ti急冷钎料钎焊Si3N4陶瓷接头界面结构及性能

采用（Ag72Cu28）％Ti4急冷钎料钎焊Si3N4陶瓷,研究联接温度、时间和压力等工艺参数对Si3N4陶瓷的接头界面结构以及强度的影响,并与同成分的常规钎料进行对比．研究结果表明：钎焊温度、保温时间和钎焊时施加的压力对钎焊接头强度均有影响,主要通过影响反应层结构和厚度来体现;Si3N4／（Ag72Cu28）96Ti4界面微观结构为Si3N4／TiN／Ti—Si化合物／Ag-Cu共晶;在相同的试验条件下,采用（Ag72Cu28）96Ti4急冷钎料钎焊的接头强度比常规钎料钎焊的接头强度提高37％．     

金塘大桥箱梁湿接头裂缝的原因分析与防治措施

本文阐述了金塘大桥非通航孔桥箱梁湿接头裂缝产生的情况,并结合现场施工的实际分析了裂缝产生的可能原因,同时为避免后期施工的湿接头产生裂缝提出了防裂措施。     

中部地区水泥路面切割缝的伸缩量测定及填缝材料的选择

阐述了填缝材料的选用原则和性能要求,对我国中部地区水泥路面的几个路段的切割缝的伸缩缝进行了实地测量,并考察了填缝材料的使用情况,发现气候差异、材料性能及是否及时对切割缝进行处理等是导致水泥混凝土路面产生各种病害的原因,提出填缝材料必须具有良好的粘结性、优良的耐候性和一定的弹性恢复能力和抗嵌入能力。