循环温度和荷载作用下能源桩-土力学特性研究

开展了建筑荷载作用下能源桩-土力学模型试验及数值模拟,分析了加热(制冷)运行对桩土力学特性的影响。首先,在桩顶分级加载至2kN,待沉降稳定后再对桩土进行加热升温冷却(室温11℃→55℃→11℃),测试了桩顶竖向位移、桩身轴力、土体温度和孔隙水压力、地表竖向位移,分析了循环温度作用下的桩-土力学特性及变化规律;其次,以模型试验为原型,利用ABAQUS软件建立能源桩桩-土计算模型,并将模拟结果与试验结果对比;最后,开展了不同循环温度作用和循环次数下的桩-土力学特性数值模拟。结果表明:在运行工况下,土中超静孔隙水压力随温升的增加而变大,使土体发生热固结现象;随循环次数的增加,桩顶及地表产生不可恢复的变形,且土的沉降大于桩体沉降,导致桩身多处出现负摩阻力,且负摩阻力随温度的升高而增大。     

复曲线及卵型曲线计算方法

针对中线设计的重要性，介绍了中线设计的方法，详细讨论了复曲线和卵型曲线的几何要素和中桩坐标的计算方法，指出导线法适用于大比例地形图上定线、优化设计和立交线形设计中。     

A comparative study between simplified and nonlinear dynamic methods for estimating liquefaction potential

This paper estimated the liquefaction potential of a saturated soil deposit subjected to a horizontal seismic excitation at its base using the total stress approach.A comparative analysis between the simplified and the nonlinear dynamic methods was used to verify to what extent the simplified method could be reliable.In order to generalise the reliability of the simplified method for any value of the maximum acceleration for the used earthquakes,a correction for the maximum acceleration less than 0.3 g was proposed based on the comparison of safety factor values determined by the dynamic method illustrated by the equivalent linear model with lumped masses and the simplified method for a given profile of soil subjected to 38 earthquakes.The nonlinear behaviour of soil was represented by two hyperbolic models:Hardin and Drnevich,and Masing.To determine the cyclic resistance ratio(CRR),the cone penetration test(CPT) based method,the standard penetration test(SPT) based method,and the shear wave velocity based method were used.The safety factor was calculated as the ratio of CRR/CSR,where CSR represents the cyclic stress ratio.The results of the proposed correction have given smaller values of the safety factor compared to the nonlinear dynamic methods for the maximum acceleration less than 0.3 g.In other words,by considering this correction,the most unfavourable case is always given by the modified simplified method.     

新型节能墙体冷负荷计算温度的研究

建立了新型节能墙体空调冷负倚计算温度的数学模型，探讨了求解冷负荷计算温度的途径，详细说明了求取空调冷负荷计算温度的方法，这对于新型墙体的空调冷负荷精确计算、空调系统的节能优化运行都具有一定的参考价值。     

天然气负荷指标及用气规律的研究

1 概述 1.1 引言 随着国内经济的迅猛发展,能源需求不断提高,作为清洁能源的天然气近年来其销售量一直在持续增长,同时天然气应用范围也在不断扩展,为了更有效地利用天然气,对天然气负荷指标和用气规律的研究尤为重要.     

单桩静载荷试验曲线的研究与应用

采用指数函数曲线拟合单桩静载试验Q—s曲线,得到了较高拟合度的参数,将参数代入指数函数获得了Q—s关系函数,可选取低于破坏荷载下的任意荷载求取沉降量,亦可求取任意沉降量条件下的桩顶反力值。     

Comparison of annual energy performances with different ventilation methods for temperature and humidity control

Stratum ventilation has been proposed to accommodate elevated indoor temperatures recommended by governments in East Asia. TRNSYS is used for computation of the space cooling loads, sensible and latent, as well as system energy consumption. Typical configurations of an office, a classroom and a retail shop in Hong Kong are investigated. Desiccant dehumidification with and without solar assistance is utilized for the air treatment under displacement ventilation and stratum ventilation, while simple reheating is adopted under mixed ventilation. Compared with mixing ventilation and displacement ventilation, stratum ventilation derives its energy saving potential largely from the following five factors: the reduction in ventilation, dehumidification and transmission loads, prolonged free cooling period and increased the COP of the chillers. For the office, the year-round energy saving is found to be substantial at 20% and 40% without the need for solar energy provision when compared with displacement ventilation and mixing ventilation respectively. For the classroom and retail shop, the year-round energy saving is at about 25% and at least 37% with the aid of solar energy provision when compared with displacement ventilation and mixing ventilation respectively.     

制作温湿度曲线图表为调控库房温湿度提供依据

为了延长档案“寿命”或者说延缓档案自然损坏的时间,采取有效措施达到控制档案库房温湿度的目的,本文阐述了如何制作档案库房温湿度曲线图表,意在避免档案工作人员每天记载库房内温湿度,减轻劳动强度,优质高效地做好档案库房的温湿度控制。     

A simple method for estimating energy saving in buildings

This paper introduces a method of selecting the most energy-saving heating system without resorting to too complex and heavy analysis requiring large computers.

The method described uses an imaginary ‘year’ of 52 days picked at random, to enable designers to calculate diary heating needs in the various cases to be considered.

In the paper the method is applied to a swimming pool for which several heating and management systems liable to be used are studied and compared.     

非标准板载荷试验对复合地基沉降的估算方法

复合地基检测一般采用单桩或多桩载荷试验方法，载荷板的面积为单桩或多桩承担的地基处理面积(此种情况本文称之标准板载荷试验)。由于实际工程中置换率变化较大给试验带来一定困难，试验荷载较大时更是如此。为此，本文通过理论推导并经实际观测证实了采用非标准承压板进行载荷试验，再用静刚度方法估算复合地基沉降的可行性，从而提高了复合地基载荷试验的适用范围、降低了试验难度，有一定的实用价值。     

Automated processes of estimating the heating and cooling load for building envelope design optimization

An automated process is developed to perform dynamic energy simulations for several hundreds or thousands of the conditions required to examine the influence of dozens of building envelope design factor changes on the heating and cooling load of a building. The developed process was applied for 10-factor 128-treatment fractional factorial design, it was experimentally confirmed that the simulated preparation period, which took about 1 day to complete via manual operation, took about 10 min using the automated process; this represents a 400-fold increase in speed. It is shown that the processing time savings obtained with the automation process increase exponentially as the number of design factors considered increases. The regression equations between heating and cooling loads and design factors are analyzed with a multi-objective optimization algorithm to obtain the Pareto-front, which is a combination of optimal design factors that can be used to minimize the building heating and cooling loads and to provide building designers with viable alternatives by considering the building energy performance.     

基于Matlab的冲击荷载下构件位移时程曲线分析

介绍了几种冲击荷载的加载方式,通过Matlab软件对不同冲击荷载作用下的位移时程曲线作了分析,得出一定的规律,对于结构抵抗偶然荷载有着至关重要的意义,同时提高建筑物的安全性。     

位能负载中变频器的选用原则及注意事项

分析了位能负载物理特性及变频调速的系统特性,并对变频器的合理选用进行了研究,介绍了位能负载工作在第二象限时,变频调速系统中应采取的相应措施。     

关于铁路曲线线路养护维修中维修方法的探讨

根据曲线线路的特点,结合现场实践,就铁路曲线线路养护中曲线缩短轨铺设和曲线方向整治两方面的方法进行了探讨,并将这两点有机的结合,以使铁路线路维修工作更加完善.     

渡槽温度荷载理论分析与计算

以黔中水利枢纽工程菜子冲湾渡槽为例,阐述了夏季日照作用下箱形渡槽热交换的影响因数及产生复杂温差分布的基本原理,并对影响渡槽温差分布的各项因素和参数值逐一进行了理论计算,分析与计算结果对箱形渡槽温度场及温度应力的研究有一定的借鉴作用。     

Regression models for estimating storm runoff load and its application to Lake Kasumigaura

Regression models are proposed for accurate estimation of storm runoff load. Regression equations are obtained for the relationship between final cumulative load and flow during direct runoff by each storm event. The models are applied to estimate annual nutrients load by all influent rivers into the Lake Kasumigaura for a model year of average annual rainfall. The load in dry weather is calculated from observed data of all influent rivers. Total annual load for a year is the sum of loads in dry weather days and loads in wet weather days. The ratios of the load in a wet weather day to total annual loads are 29 percent for T‐N, 51 percent for T‐P, 53 percent for T‐COD, 22 percent for D‐N, 22 percent for D‐P and 30 percent for D‐COD.     

结构需求概率危险性分析中强震记录选取研究#br#

目前结构性态地震工程中易损性曲线传统计算流程对强震记录选取不够重视,鲜有对目标场址地震概率危险性的考虑,因而以同时考虑地震概率危险性和结构自振周期特性的条件均值谱作为记录选取依据,将结果应用到IDA方法和条带法中,并与地震事件随机散布的传统云图法进行对比。以某八层平面框架作为算例,将云图法与IDA方法以及条带法在四种极限状态下的结构需求易损性曲线以及结构需求概率危险性曲线进行对比分析。其中,随机选取两组地震事件（M,R）分布范围相仿的强震记录进行云图法计算,二者结果由于不可控的地震动不确定性而存在显著差异,但IDA方法与条带法由于采用条件均值谱对地震动进行了控制,彼此结果基本一致,更符合实际工程场址的危险性需求,同时为后期不同区域的结构性态分析损失评估提供了依据。     

A study on estimating the energetic and exergetic prices of various residential energy sources

In choosing the type of any energy sources for residential and other uses, their prices play in general a big role. These prices are based on energy values. Besides this, the application of the exergy, which is a way to a sustainable future, is more meaningful in providing information for long-term planning of resource management. In the present study, energy and exergy prices of various energy sources are investigated. The energy sources considered include coal, natural gas, furnace oil, diesel oil, liquefied petroleum gas (LPG) and wood, while electric resistance along with heat pump and district heating are also covered. In this context, chemical exergy relations of these energy sources are presented first. The prices of various energy sources in the Turkish residential sector, which is given as an illustrative example, are then used in the calculations. Finally, the energy and exergy prices are compared with each other, while the main conclusions are listed. The highest unit energy price is that of diesel oil, while the lowest one is that of natural gas. The differences between the energy and exergy prices are small for all energy carriers.     

建筑能耗评估中对气象参数的处理

对建筑能耗按照气候条件进行修正是建筑能耗评估的基础，也是提高建筑能耗评估精度的关键。本文讨论了目前通用的修正方法(DD法和EDD法)，指出这些方法虽然具有较高的精度，但缺陷也显而易见，并提出了改进建议。     

Outdoor synthetic temperature for the calculation of space heating load

Methods to select the outdoor design temperature (ODT) for heating load calculation specified in current design codes in different countries are firstly discussed. Then a new method namely Stochastic Analysis is presented to determine the outdoor synthetic temperature (OST), which fully considers the randomness of weather and internal casual gains, and the thermal performance of buildings. The concept of OST enables the design of space heating system to be the trade-off between economics and risk. Finally, case studies of the influence of different building components on OST of a residential room in Beijing have been studied, which shows that OST depends upon building structures as well as weather conditions. It is recommended that OST rather than ODT should be employed in heating load calculation hence, sizing equipment for space heating systems.