Experimental Research of Hexagon Multihole Armour Block on Breakwater

This paper introduces a new kind of armour block - hexagon multihole block on sloping breakwater. It has great characteristics such as good interlocking, strong resistance against waves and saving concrete. Through the hydraulic model test, the mechanism of stability of the block has been proved and the relations between stability and wave height, wave period, water depth, slope, laying method, porosity and cushion have been found. The effect of weight on steadiness have also been discovered. Finally, the method of design and some formulas are given.     

Experimental Research on Sewage Outfall Diffusers

The influence of diffuser parameters, including the riser spacing, port number in a riser, injection angle, port arrangement, etc., on the surface initial dilution is experimentally investigated. The relative density difference between the effluent and the sea water in the model is the same as that in the prototype, and the effect of the cross current is simulated by an inverse model technique. Based on the result analysis, the arrangement with more ports in a riser and larger riser spacing is suggested to save construction cost. The relationship between the Reynolds number based on the port diameter and velocity, and the surface initial dilution is also explored, and the critical Reynolds number is proposed.     

Some Problems in the Design of Breakwaters in Dayaowan Port Area

- In this paper, some problems in the design of the breakwater for Dayaowan port area are described including the optimal selection of the layout plan of the breakwater; the selection of structural type of the breakwater, the concrete block type for bank protection, the reversed L-shape parapet; the elevation of the parapet; the stability test of the whole revetment; as well as wave absorbing effects of the perforated     

Experiment for Determination of Dry-Laid Stone Armour Layer Thickness of Rubble Mound Breakwaters

Through hydraulic model experiment and site investigation, this paper has derived a calculation formula of dry-laid stone armour layer thickness of rubble mound breakwaters for fishery harbours. The influences of the friction force between stone blocks and the variations of wave length or period and water depth are considered in the formula. The calculated results of several existing structures are in good agreement with field data. This formula is more practical than those ever published both at home and abroad, and has been adoptted by the technical standards of aquatic projects published by the Ministry of Agriculture of China. It is applicable for the calculation of dry-laid stone armour layer of breakwater for small- or medium-size harbours.     

Numerical Simulation of Residual Circulation due to Bottom Roughness Variability Under Tidal Flows in A Semi-Enclosed Bay

1 .IntroductionWater pollution has a large influence on water environment and our life ;for example ,it some-times induces oxygen depression,blue tide andredtide in a bay.For water purificationin a semi-en-closed sea ,some new methods to activate the tidal exchange between an inner bay and an outer seaarea by control of a tidal residual current have been proposed (Awayaet al .,1995) . Huthnance(1973) ,Zimmerman (1978 ,1981) , Loder (1980) ,and Robinson (1983) considered cases wherethe fricti…     

DEFORMATION AND ROUGHNESS CHANGES OF THE MAIN CHANNEL AND FLOODPLAIN IN FLOOD EVENTS (CASE STUDY )

LINTRODUCTIONAsfear7specificsurveyshavebeenmadeonthemorphologicalbehavioroftheHuaihefox'erinthepast.Someinformationofbeddeformationduringfloodprocesshavebeenobtained.Beingrelativelystable,theHuaihehiverusedtobeineptlytreatedas"fixedbed".Fortunately,tilehydrometricalstationsweredenselydistributedalongtheHuaihehiverinthe1950s,andthevelocitylareamethodwasusedforthedeterminationofdischarge.Themeasurementsofdischargearelistedin"TheDischargeMeasurementsTable"intheHydrologicalYearbooks.Sinc…     

Response of Coastal Groundwater Table to Offshore Storms

Large groundwater table fluctuations were observed in a coastal aquifer during an offshore storm. The storm induced significant changes of the mean shoreline elevation, characterized by a pulse-like oscillation. This pulse propagated in the aquifer, resulting in the water table fluctuations. A general analytical solution is derived to quantify this new mechanism of water table fluctuation. The solution is applied to field observations and is found to be able to predict reasonably well the observed storm-induced water table fluctuations. Based on the analytical solution, the damping characteristics and phase shift of the oscillation as it propagates inland are examined.     

城市环境地球化学研究综述

近年来地球科学越来越多地面向城市,城市环境受到人类活动的广泛影响,自然及人类活动引起的城市地球化学问题日益受到人们的重视。城市环境地球化学是应用地球化学的原理和方法研究城市生态环境问题,主要研究城市土壤、沉积物、尘埃、地表水、地下水、生物、空气等介质中化学元素及同位素的分布、演化、环境作用及健康效应,重点解决城市地球化学环境质量变化的原理及由此产生的生态环境效应及人体健康效应。城市环境地球化学的主要研究对象是传统工业城市、典型矿业城市及国际化的大都市。在城市地球化学概念出现之后短短的10余年时间内,很多国家开展了城市环境地球化学调查和研究工作,取得了重要的成果和进展,并发展成为环境地球化学与城市环境的重要方向,但仍存在着一定的问题,需要深入研究。目前,城市环境系统的地球化学填图、城市地球化学与环境污染研究、城市地球化学与生态风险研究、城市地球化学与人体健康研究、城市地球化学系统的调控与环境规划等领域是国际城市环境地球化学的热点和前沿。     

The Changing Cold Regions Network:Observation,diagnosis and prediction of environmental change in the Saskatchewan and Mackenzie River Basins,Canada

Climate change is causing rapid and severe changes to many Earth systems and processes,with widespread cryospheric,ecological,and hydrological impacts globally,and especially in high northern latitudes.This is of major societal concern and there is an urgent need for improved understanding and predictive tools for environmental management.The Changing Cold Regions Network(CCRN)is a Canadian research consortium with a focus to integrate existing and new experimental data with modelling and remote sensing products to understand,diagnose,and predict changing land,water,and climate,and their interactions and feedbacks over the geographic domain of the Mackenzie and Saskatchewan River Basins in Canada.The network operates a set of 14 unique and focused Water,Ecosystem,Cryosphere and Climate(WECC)observatories within this region,which provide opportunities to observe and understand processes and their interaction,as well as develop and test numerical simulation models,and provide validation data for remote sensing products.This paper describes this network and its observational,experimental,and modelling programme.An overview of many of the recent Earth system changes observed across the study region is provided,and some local insights from WECC observatories that may partly explain regional patterns and trends are described.Several of the model products being developed are discussed,and linkages with the local to international user community are reviewed—In particular,the use of WECC data towards model and remote sensing product calibration and validation is highlighted.Some future activities and prospects for the network are also presented at the end of the paper.     

碎石土振动压实动态监测方法研究

根据结构振动理论,分析了振动压实机械与被压土体的相互作用机理,研究了碎石土振动压实动态监测的理论依据,建立了一套适用于加速度监测仪的振动压实动态监测数据采集系统．在大量室内试验数据的基础上,研究了振动压实过程中加速度电信号响应随碎石土密实度的变化规律,发现二者具有显著的线性相关性．研究结果为实现快速有效的碎石土路基密实度实时动态监测提供了理论依据和工程指导．