县乡公路沥青混合料机拌机铺施工中质量管理探讨

传统的县乡公路油化施工工艺已不能满足当前交通发展的需要,为提高县乡公路油化机拌机铺施工工程质量,从原材料选择、试验、配合比设计与施工机械选用、施工组织生产、施工工艺等方面,提出了建议.     

高钙粉煤灰软土加固机理的研究

通过对高钙粉煤灰的物理、化学性质的分析试验 ,研究高钙粉煤灰及软土加固后的结构及高钙粉煤灰加固软土的机理 .高钙粉煤灰与软土拌和后可以形成连续性、水稳性较好的坚硬拌和桩体 .     

普通混凝土配合比设计应注意的几个问题

普通混凝土由水泥、掺合料、外加剂、砂、石、水6大原材料组成,每种原材料都发挥着各自特有且不可替代的作用。文章分析探讨了普通混凝土配合比设计中值得注意的几个问题,并提出了相应的防治措施,以使混凝土的配合比达到工程要求。     

冷再生二灰碎石基层厚度控制

冷再生二灰碎石基层是较新颖的结构形式,在旧路改建工程中有很强的应用前景。由于旧路面受到破坏,平整度差,该结构层的厚度控制在实际施工中是个难点。结合某路面翻修工程实例,阐述通过高程和拌和工艺双重控制,可以使该结构层的厚度指标达到规范要求,不会再出现夹层或结合料含量减少现象。     

One-dimensional modelling of the plankton ecosystem of the north-western Corsican coastal area in relation to meteorological constraints

In order to study the influence of wind mixing on the spring variability of the plankton production of the north western Corsican coastal area, a one-dimensional (1D), vertical, coupled hydrodynamic/biological model (ECOHYDROMV) is used. A hydrodynamic 1D model of the water column with a k–l turbulent closure is applied. The biological model comprises six state variables, representing the plankton ecosystem in the spring period: phytoplankton, copepods, nitrate, ammonium, particulate organic matter of phytoplanktonic origin and particulate organic matter of zooplanktonic origin. The system is influenced by turbulence (expressed by the vertical eddy diffusivity), temperature and irradiance. The model takes into account momentum and heat surface fluxes computed from meteorological data in order to simulate a typical spring atmospheric forcing for the considered area. Results show that primary production vertical structure is characterised by a subsurface maximum which deepens with time and is regulated by the opposite gradients of nitrate concentration and irradiance. Surface plankton productivity is mainly controlled by turbulent vertical transport of nutrients into the mixed layer. The short time scale variability of turbulent mixing generated by the wind appears to be responsible for the plurimodal shape of plankton blooms, observed in the considered area. Furthermore, the model is applied to the study of the spring evolution of the plankton communities off the bay of Calvi (Corsica) for the years 1986 and 1988. In order to initiate and validate the model, time series of hydrological, chemical and biological data have been used. The model reproduces accurately the spring evolution of the phytoplankton biomass measured in situ and illustrates that its strong variability in those years was in close relation to the variability of the wind intensity.     

基于遗传算法的长江堤防深搅桩加固措施优化及稳定分析

针对长江堤防特点,重点分析了扬州市小河口至潘家河口段堤防安全稳定问题,选取3个典型断面进行稳定计算,并采用遗传算法对深搅桩加固范围进行优化搜索。同时考虑长江堤防区别于一般河道设计的防浪要求,总结提出了适合于长江堤防整治的堤坡草皮和防浪林带绿化设计。研究发现,长江堤防加固采用套打搅拌桩的处理措施可以有效进行截渗,提高提防安全系数约30%,从而使得长江江港堤防防洪标准提高至100 a一遇。     

水泥搅拌桩在高填方软基路段的探索与应用

为解决水泥搅拌桩在高填方软基路段的应用难题,以高恩高速公路K20+076~K20+513段软基处理为例,通过施工方案比选与工艺优化,对推荐方案进行了稳定性验算,对成桩后的水泥搅拌桩进行了承载力试验,对软基路段进行了应力和位移监测。结果表明,在填土高度8 m^14 m的软基路段,水泥搅拌桩复合地基综合处理方案可行,质量可控,造价合理,可供类似工程参考。     

Three-dimensional hydrostatic modeling of a bay coastal area

This article describes the development of a three-dimensional (3D) multilayer hydrostatic model of tidal motions in the Ariake Sea and its application. The governing equations were derived from 3D Navier-Stokes equations and were solved using the fractional step method, which combines the finite difference method in the horizontal plane and the finite element method in the vertical plane. This study introduced a 3D, time-dependent, hydrostatic, tidal current model that can compute wetting and drying in tidal flats due to tidal motion. The 3D model was first tested against analytical solutions for three standard cases in a rectangular basin in order to investigate the performance of the model. Then, the model was applied to Saigo fishery port and the Ariake Sea. For standard cases, the numerical solutions were almost identical to the analytical solutions. Finally, the model results for Saigo port and the Ariake Sea show good agreement with the field observations.     

水泥土搅拌桩在地基整体稳定加固中的应用

以浙江省某船闸引航道工程为背景,介绍水泥土搅拌桩在处理软土地基和导航、靠船及护岸建筑物整体稳定中的应用。通过计算分析及观测表明,采用水泥土搅拌桩加固软土地区地基整体稳定的方案,处理效果明显,造价经济。     

沥青拌和机中的计算机系统

分析了沥青拌和机中计算机系统的重要性,着重阐述了2台计算机应用软件的设计原则、主要功能及其硬件连接,给出计算机控制系统的结构流程图。通过实际应用证明此计算机控制系统运行稳定可靠、级配精确、操作简便。