温室结构快速建模方法的研究

主要讨论了温室结构快速建模的一种简单而有效的方法，并通过实例进行了说明，指出该方法利用已有的结构建模软件根据温室施工图建立模型，生成模型文件，用户根据需要适当修改该文件，在温室结构建模时调用该文件，从而可快速生成模型，以推广它的应用。     

改良型中档温室供热系统的研究和设计

农业温室是具有必要技术设备的，能够常年为作物生长和发展提供所需条件的特殊建筑物，温室是一个特殊的生产车间、冬季供热。本文结合课题研究和示范工程温室的设计，着重介绍了温室的型式、覆盖材料、热负荷计算、温室的供热系统型式以及节能运行方式等。     

屋顶温室的耗热量计算

简述屋顶温室节水、节能、节地和治污等优点。阐述其不同于普通地面温室的耗热量计算方法 ,并组出围护结构基本耗热量计算结果 ,供设计时参考。     

适宜重庆冬季温室供暖的稻草燃池研究

为解决重庆温室冬季供暖问题,在总结前人关于温室供暖与燃池的建设方法的基础下,自主设计给8×30×3m温室供暖的燃池,计算结果给出了燃池的大小、进气口的大小及出气口的大小及长度等计算方法。重点计算了燃池供暖温室的年耗热量、燃池供热面积;确定了燃池在温室的空间位置;燃池出气及进气量的设计,并给出了建造燃池的施工建设要点,为重庆温室建设燃池提供依据。     

西咸新区某地热供热项目碳减排量计算及分析

地热是一种稳定的可再生清洁能源,储量大、分布范围广,是替代化石能源、实现低碳供热的重要选项。西咸新区某新建公共建筑采用中深层地热为建筑提供冬季采暖热源,可减少温室气体排放。利用CDM方法学AM0072计算地热替代化石能源的供热项目温室气体减排量,该项目每年可减少温室气体排放150.08 tCO₂e;对于类似项目,基准线排放量的确定受燃料种类和设备燃烧效率的影响,燃料的CO₂排放因子越大,基准线排放量越高,当设备燃烧效率由75%提高到92%时,基准线排放量降低了18.4%;不同计算方法对项目减排量结果影响较大,利用节煤减排量计算出的结果是CDM方法学AM0072计算出的3.28倍。     

原油储罐温室气体排放核算方法研究

原油储罐是油气生产上游环节中不可忽略的温室气体逸散排放源。为探究原油储罐温室气体排放情况,对储罐温室气体排放过程进行分析,建立基于气体状态方程、连续性方程和绝热条件下的能量方程的储罐小呼吸温室气体排放核算模型,修正Vasquez-Beggs(VB)闪蒸排放模型,得到一次、二次沉降罐和净化罐温室气体排放核算方法,并与实测数据、API经验公式计算值进行对比。结果表明:储罐温室气体排放的理论计算与实际情况吻合较好,所修正的VB模型与小呼吸损耗模型可准确地评估原油储罐温室气体的排放量;储罐小呼吸损耗与闪蒸损失相比不能忽略,验证了模型的准确性。     

连栋塑料温室结构的优化设计

从结构优化的角度着手 ,就结构选型、结构计算及几何参数的确定 ,详细介绍了华东型连栋塑料温室的设计。总结出一套实用的连栋塑料温室设计的方法 ,以供设计人员参考。     

新型蓄热保温材料研究获突破

据悉，西北农林科技大学园艺学院教授利用一种新型材料一相变材料和建筑材料制成墙体砌块，并以此建造了相变蓄热温室，同时还建造了一个同厚度的普通墙体材料对照温室。经试验证明．相变材料的保温蓄热作用稳定，相变蓄热温室的蓄热保温作用有利于温室作物的生长。     

农业温室通风的研究与设计

中档连栋薄膜温室是一个大面积的农业温室,类似于多跨度的工业厂房。与单栋温室相比,其通风方式其特殊性。本文论述了农业温室的通风方式,并提出了通风计算方法。     

温室降温

本文译自美国北卡罗纳州大学paul V.Nelson教授于1978年编著的“Greenhouse Op-eration and Management”一书中的有关章节—Greenhouse Cooling。主要介绍温室水蒸发降温系统的原理、结构、布局及设计计算方法等。为我国温室事业的发展具有一定参考价值。     

箱肋拱桥施工技术

结合工程实例,介绍了箱肋拱桥施工技术,从箱肋拱桥的特点、拱肋的施工、拱肋的吊装等方面进行了论述,指出箱肋拱桥的施工技术,具有结构简单、自重轻、跨度大、造价低、施工方便、工期短、质量保证、外型美观等特点,值得推广应用。     

飞雁式拱桥边拱支架施工技术

根据某工程边拱施工的实际情况,对飞雁式拱桥边拱支架施工进行了设计与研究,有效的解决了在河床上边拱施工的难点,并取得了一定的经济效果,为类似的工程施工积累了经验。     

Modelling autogenous expansion for magnesia concrete in arch dams

Magnesia Concrete is a kind of expansive concrete used in Chinese hydraulic engineering more and more widely. To evaluate the effects of autogenous expansion on the stresses of arch dams, a simple model of autogenous expansion for Magnesia Concrete in dam engineering is presented. This model is based on three assumptions: 1) the total amount of autogenous expansion of Magnesia Concrete is related only to the properties of materials and mixing of concrete; 2) the autogenous expansion of Magnesia Concrete is irreversible due to the irreversibility of hydration reaction of Magnesia in the concrete; 3) the autogenous expansion strain rates of Magnesia Concrete bear a relation between temperature and residual Magnesia per unit volume of concrete. The model is verified by some experimental data of autogenous expansion of Magnesia Concrete and field-measured data of an arch dam in China. Embedded into finite element arch dam simulation software, this model is employed to simulate the effects of autogenous expansion of Magnesia Concrete in hydraulic engineering.     

Modelling autogenous expansion for magnesia concrete in arch dams

Magnesia Concrete is a kind of expansive concrete used in Chinese hydraulic engineering more and more widely. To evaluate the effects of autogenous expansion on the stresses of arch dams, a simple model of autogenous expansion for Magnesia Concrete in dam engineering is presented. This model is based on three assumptions: 1) the total amount of autogenous expansion of Magnesia Concrete is related only to the properties of materials and mixing of concrete; 2) the autogenous expansion of Magnesia Concrete is irreversible due to the irreversibility of hydration reaction of Magnesia in the concrete; 3) the autogenous expansion strain rates of Magnesia Concrete bear a relation between temperature and residual Magnesia per unit volume of concrete. The model is verified by some experimental data of autogenous expansion of Magnesia Concrete and field-measured data of an arch dam in China. Embedded into finite element arch dam simulation software, this model is employed to simulate the effects of autogenous expansion of Magnesia Concrete in hydraulic engineering.     

三拱肋钢管混凝土系杆拱桥拱脚局部应力分析

针对三拱肋钢管混凝土系杆拱桥的拱脚,采用有限元程序建立了中拱肋拱脚节点的有限元模型,分析了在多种工况作用下的拱脚区域的应力分布和受力机理,计算结果表明:设计时需要注意对拱脚和拱肋相接处、支座支撑处、系杆与端横梁连接处等位置采取局部钢筋网的加强等措施以分散应力。     

钢管拱桥拱肋脱空负压灌浆修复技术研究与应用

钢管拱桥是一种常见的公路桥梁型式,但拱肋混凝土脱空是此类桥梁常见的病害。本文针对此问题,以高强度、低粘度、高渗透、耐低温、高柔性灌浆材料在模拟试验研究中所表现出的优异性能为例证,说明本材料在钢管拱桥拱肋脱空病害处治中所具有的优势。本试验的研究成果对拱肋混凝土脱空病害的处理有实际的应用意义。     

The nonconventional thin-walled arch rib design and its numerical verification of a long span steel arch bridge

Arch bridges have been widely constructed in China owing to their versatile structural configurations and competitive costs. The concept of using high performance prestressed steel wires to withstand the huge horizontal thrust at arch ends has greatly encouraged the engineering practices of large span arch type bridges constructed on soft soil foundations where normally arch structure is an inappropriate selection. However, many technical challenges including the design details, structural behavior and construction method still need to be carefully investigated to ensure the bridge′s safety. As a new practice of such tied arch bridge with nonconventional thin-walled steel box rib and the longest span of this type in the world, this paper presents the innovative design concept and the corresponding studies in regard to its structural behavior compared with conventional single arch design, the shear lag effect of the thin-walled arch rib and its stress distribution via numerical analysis of different finite element models are also investigated. The results show that the current design can reach a very good structural behavior under design load cases, and moreover, provides another very useful engineering practice for long span arch bridge constructed on soft soil foundations.     

外倾拱肋系杆拱桥的设计与施工实践

某桥梁工程是座下承式外倾拱肋系杆拱桥,主桥跨径111m,拱肋采用箱形截面,本文结合该桥的设计情况,浅析该类桥型的设计构思、造型特点和受力特性,以及施工方案的选择和施工方法。     

肋拱桥拱肋结构表观缺损状况评定标准研究

应用损伤理论,在考虑材料非线性对拱肋承载能力影响的基础上,采用ABAQUS有限元软件模拟钢筋混凝土肋拱桥拱肋开裂损伤状态,对拱顶附近裂缝数量对拱肋承载能力的影响进行了仿真分析,根据有限元的模拟结果对拱肋技术状况评定标准进行了扩充,以便作出准确评估。     

钢管混凝土拱桥主拱圈稳定性分析

以钢管混凝土拱桥的主拱为研究对象，对拱圈的稳定性进行线性屈曲和非线性屈曲分析，重点分析了横撑对主拱稳定性安全系数的影响，并对横撑的合理布置进行了探讨。