基于流变特性的消石灰改性油污泥热解残渣沥青胶浆稳定性研究

为探究油污泥热解残渣沥青胶浆性能，实现其在道路工程中的应用，开展了消石灰改性油污泥热解残渣沥青胶浆稳定性与改性机理研究。通过扫描电镜和红外光谱试验分析油污泥热解残渣的理化性质；在此基础上通过沥青胶浆三大指标和黏度试验，解析消石灰改性油污泥热解残渣沥青胶浆的掺配比；通过沥青弯曲蠕变劲度(BBR)和动态剪切流变(DSR)等试验评价了消石灰改性油污泥热解残渣沥青胶浆水稳定性能及高低温流变性能；最后通过微观试验解析消石灰改性油污泥热解残渣沥青胶浆的微观界面特性和改性机理。结果表明：油污泥热解残渣存在以中大孔为主、微小孔为辅的多孔体系，经消石灰改性后的油污泥热解残渣与沥青之间存在较强的物理吸附作用与化学吸附作用，提高了油污泥热解残渣与沥青之间的黏结力；消石灰掺量占填料总质量的30%时，其对油污泥热解残渣沥青胶浆的改性效果最佳；当粉胶比为1.0,消石灰掺量为30%时，与普通矿粉沥青胶浆相比，其水煮后的质量损失率减小了18.2%;-6℃、-12℃、-18℃时的蠕变劲度分别降低18.3%、16.5%、5.4%;64℃、70℃、76℃、82℃时的抗车辙因子分别降低6.9%、7.4%、3.3%、1.4%。...     

A numerical study on the installation configuration design of compliant vertical access riser (CVAR) in deepwater

In oil and gas transportation, the compliant vertical access riser (CVAR) system conducts economic and operational advantages due to its special configuration. In this paper, the static performance of the CVAR is studied by an efficient numerical method. According to the unique configuration of the CVAR, the mathematical model is established based on minimum total potential energy principle. The equilibrium equations are discretized by finite difference method and then solved by Newton-Raphson technique. The accuracy of the numerical method is verified by OrcaFlex software. Detailed parametric analysis is carried out based on practical engineering requirements. The effects of buoyancy section's configuration including buoyancy factor, buoyancy section's length and buoyancy section's location, and external environmental factors including wellhead offset distance, water depth and current velocity on installation shape and mechanical properties of the CVAR are analyzed. The research shows that the presented numerical method has good applicability and flexibility for the early installation configuration design of marine risers which have no touchdown section but only one touchdown point and are equipped with multiple buoyancy blocks subjected to forces of different directions and magnitudes, such as CVARs.     

跨江大桥对天星洲尾演变的影响及护滩对策

天星洲是长江下游的江心洲，拟建常泰长江大桥北侧桥墩布设与天星洲尾相毗邻。通过物理模型试验，研究常泰长江大桥的建设对天星洲尾演变的影响。结果表明，常泰长江大桥建设后，天星洲尾冲刷幅度较工程前有所增加，不利于天星洲夹槽的稳定，需要对天星洲尾进行护滩守护。与潜堤高程较高的护滩方案相比，低潜堤方案引起天星洲沙尾附近流速增幅稍小，幅度一般在0.03 m/s以内，引起天星洲夹槽流速减幅稍小，幅度一般在0.02 m/s以内，更有利于天星洲尾的稳定和七圩临时航道的水深维护。工程实施可守护天星洲尾，七圩临时航道桥位下游附近略有冲刷，有利于航道水深维护。     

临涣船闸下游引航道优化设计

临涣船闸位于临涣节制闸南侧，上距省界李口集约30.0 km,下距南坪闸31.5 km,下游引航道连接段位于转弯河段，弯道转角约75°。受此地形影响，河道主流贴右岸凸嘴进入下游主河槽，使引航道连接段与凹岸之间形成逆时针回流，对引航道水流有压迫作用，局部主流宽度显著束窄。通过物模试验可知，河道主流对引航道口门区内水流形成较为明显的剪切，导致口门区内形成较大范围的回流，长度近350 m。由于回流区较长，形成多个复杂的异向回流组合流态，水流条件十分复杂，因此需提出相应的工程措施加以改善。通过河槽疏浚、增加隔流潜堤，有效地解决了下游引航道水流流态不佳、横向流速超标较大、口门区回流强度较大、回流流速无法满足规范要求的问题。     

鄱阳湖水利枢纽航道通航水流条件及优化措施试验研究*

针对鄱阳湖水利枢纽通航水流条件是否满足通航安全要求展开研究，建立鄱阳湖入江水道星子—湖山段物理模型，对鄱阳湖水利枢纽一期围堰阶段现状航道、二期围堰及运营期设计航道各典型工况下的通航水流条件进行试验研究。首先通过物理模型试验验证航道内是否产生不良流态；其次针对航道内出现的不良流态提出相应优化措施并进行方案比选；最后对优化后航道内通航水流条件进行试验验证以确保船舶安全通航。模型试验主要结论：二期围堰及运营期设计航道在大流量工况下存在上游口门区横向流速超标及下游锚地段生成大尺度回流等问题。通过实施调整上游隔流堤形式，航道右侧浅滩开挖，下游锚地段下移等措施后，设计航道各工况下水流条件均满足通航安全要求。     

面向刚度设计的 GFRP 和 VRB/GFRP 混合层合板应变能密度分布研究

针对 VRB/GFRP混合结构刚度优化设计复杂而耗时这一问题，利用有限元法分析了 GFRP铺层角度和铺层数量、VRB厚度分布形式对两种层合板刚度特性及各组分应变能密度分布的影响规律。研究结果表明，应变能密度越小能表征更好的刚度性能；抗弯与抗凹工况下，采用# （0/90） 铺层角度、增加 GFRP铺层数量以及 VRB采用 0.9-1.8-0.9 mm 的厚度分布形式时，VRB/GFRP层合板各组分的应变能密度分布更加均匀，从而获得更好的刚度性能。     

圆环联锁型生态护岸结构稳定性试验研究

现有生态护岸以稳定性为主，考虑生态性较少。为改善岸坡的生态性，提出一种圆环联锁型生态护岸结构。为探究该生态护岸结构在建设初期(无植被时)的稳定性及防护效果，通过动床实验对比不同防护措施下岸坡的稳定性，并研究流速对护岸结构稳定性及防护效果的影响。研究结果表明：1)圆环联锁型生态护岸结构可有效减少岸坡冲刷面积和冲刷深度，增强岸坡稳定性；2)其失稳形式有2种，分别为因坡脚变形而下滑失稳和因岸坡淘刷而下陷失稳；3)其冲刷面积和最大冲刷深度随流速增大而增大，二者的增率随流速增加而减小。     

Ultimate strength assessment of simply supported pitted platings: A new stochastic approach based on Monte Carlo simulation

The ultimate strength assessment of platings affected by random corrosion wastage is a key factor for the reliable design of new ships and the structural health monitoring of aged structures, as pitting corrosion wastage significantly affects the ultimate capacity of platings under compression. In this respect, significant efforts have been undertaken in the last decade to assess the ultimate strength drop-off of pitted platings under compression and several interpolating design formulas, based on a large number of FE simulations, have been developed. Nevertheless, current Rules and guidelines don't provide any explicit strength check criterion for pitted platings. Hence, the main aim of current research is the development of a new framework for the ultimate strength assessment of pitted platings, based on a stochastic approach and the endorsement of Monte Carlo simulation. A new formula, which allows evaluating the statistical properties of the plating ultimate strength in presence of random corrosion wastage, is developed. Subsequently, a benchmark study is carried out, to compare the new formula with the existing ones available in literature and a wide set of FE simulations, carried out by Ansys APDL. Current results are discussed, and the effectiveness of the new formula is verified.     

波纹钢板截面几何性质精确计算

为快捷、精确地计算波纹钢板截面几何性质，通过各截面几何性质的定义推导得出单位长度波纹钢板截面面积、惯性矩、截面模量、回转半径的精确计算公式，并将其编写为“波纹钢板截面几何性质计算器”程序。以两种波形为计算实例，将编写程序的计算结果与现有文献和CAD软件计算结果对比，结果表明：计算结果与CAD软件计算结果完全吻合，而现有文献中的计算结果均存在误差，为近似值。可见，推导的计算公式及编写的“波纹钢板截面几何性质计算器”程序可精确计算波纹钢板截面几何性质。     

水下不分散混凝土试验研究

对水下不分散混凝土物理力学性能进行了试验研究,推荐配合比的水下不分散混凝土具有粘稠、流动性好、高水下抗分散性和低弹模高塑性的特点,经济可行,施工方便。