富浆CSG筑坝材料现场碾压试验研究

富浆CSG筑坝材料是一种新型的筑坝材料,通过对富浆CSG混凝土现场碾压试验研究,给出了推荐的碾压参数:铺料厚度50 cm,静压2遍,振动碾压6遍,Vc为2～8 s。该筑坝材料应用最大限度的解决骨料紧张的问题,缩短了工期,试验研究结论为其他富浆CSG筑坝材料碾压施工提供了技术参数。     

高粉煤灰含量碾压混凝土及其优越性

一、引言碾压混凝土筑坝是七十年代初期在美、英、日等国发展起来的一种新技术。它采用通仓薄层浇筑、振动碾压实的方法施工,突破了传统坝工混凝土施工所用的柱状浇筑方法,因而大大简化以至取消温控措施。它的出现和推广是筑坝技术的一次革命。筑坝用碾压混凝土有三种主要类型:(1)干贫碾压混凝土:胶凝材料(水泥 粉煤灰)用量120公斤/米~3左右,其中粉煤灰含量为胶凝材料总重量的20～30％;(2)高     

土石坝坝体填筑施工方法探讨

坝体大多是用来挡水的建筑物。筑坝技术发展至今,出现了许多新的筑坝材料与方式,但土石坝以其建筑方式简单、节省材料、能够就地取材、防水效果好等优点而被一直沿用。本文对土石坝坝体填筑施工方法进行了分析。     

水利水电施工中筑坝工程的工艺研究

随着我国社会经济的快速发展,特别是基础设施建设的不断深入,水利水电工程得到了长足的发展。水利水电工程是我国关乎国计民生的一项利民工程,对我国的经济发展以及社会稳定具有重要的意义。筑坝工程是水利水电施工中重要的组成部分,而混凝土碾压施工是筑坝工程施工重要的施工工艺,具有成本低、工期短等优点。本文首先分析碾压混凝土施工工艺的特点,并水利水电施工筑坝工程关键工艺进行详细的探讨。     

水利水电施工中筑坝工程的关键工艺分析

随着社会的进步和科技的发展,水利水电工程施工技术也得到了进一步提高,筑坝工程作为水利水电工程常见项目,其施工工艺水平决定了整个工程的施工质量,影响极大。筑坝是一种十分常见的水利水电施工类型,筑坝建设是水利水电工程的重要组成部分,施工工艺要求较高。在施工过程中,应全面掌握各种关键工艺,提高施工水平,从而提高工程质量。本文主要分析了水利水电筑坝工程施工过程中的几种关键工艺,以期作为水利水电工程施工参考。     

新型碾压混凝土施工机械--洒浆机

变态混凝土的形成是通过在碾压混凝土摊铺层泼洒水泥浆，使之变成具有塌落度的常态混凝土，然后用插入式振捣器使之密实。它是为了实现全断面碾压混凝土筑坝目的而新近发展起来的一种施工技术，已在荣地、石漫滩、汾河二库、棉花滩等碾压混凝土坝中采用，效果显著，正逐渐发展成为碾压混凝土筑坝     

CSG坝筑坝材料特性与抗荷载能力研究

胶凝砂砾石坝(CSG)是介于混凝土面板堆石坝(CFRD)和碾压混凝土重力坝(RCC)之间的一种新坝型。其显著的特点是:胶凝材料用量少,对筑坝材料要求低,坝体和地基受力条件好,是一种环保性能、力学和大坝安全性能都很有竞争力的新筑坝技术。通过福建省龙岩白沙大坝、宁德洪口大坝的围堰以及尤溪街面大坝围堰等3个工程,对CSG坝的筑坝材料和抗荷载能力进行分析研究,并在街面工程的下游围堰进行局部CSG坝的工程实践。研究表明:CSG坝的水泥用量约为RCC重力坝的42.9%～49.1%左右,大坝断面可较CFRD坝减少100%,大坝位移量与RCC坝相当,而只有CFRD坝的1/20～1/10。不仅如此,CSG坝体受力条件明显改善,竣工期与运行期坝体内应力变化不大,大坝抗震能力明显增强。     

辉长岩人工骨料在水工混凝土中应用研究

对辉长岩矿物成分、物理力学性质、碱活性及轧制而成的人工骨料混凝土配合比,混凝土力学、耐久性、热学、变形性和抗裂性等特性进行了研究,并与灰岩、花岗岩等骨料的混凝土性能进行了比较。结果表明:辉长岩具有良好的物理力学性质指标,混凝土强度性能、拉伸性能、抗冻性能等较好,可用作水工混凝土骨料,但混凝土线膨胀系数、干缩率偏大,减少混凝土干缩、冷缩等收缩变形是提高辉长岩混凝土抗裂性能的重要措施,在应用过程中宜从配合比优化和施工控制两方面进行,成果为采用辉长岩作为筑坝材料的工程提供重要技术依据。     

某水库软岩筑坝材料试验研究

随着筑坝技术的发展,利用软岩筑坝的工程已经越来越多,对某水库P1料场软岩堆石料筑坝进行了试验研究,为设计提供合理的参数,可以更好的利用当地材料,并且节约工程投资,取得良好的社会效益和经济效益。     

碾压混凝土筑坝材料配合比参数的选择及发展趋势

自碾压混凝土筑坝技术引入我国以来,该技术不断进步,应用规模不断扩大.本文总结了多年来我国碾压混凝土坝的筑坝材料研究成果,分析、归纳了碾压混凝土筑坝材料配合比参数选择及发展趋势.     

Adaptability to geological faulted foundation of Hardfill dam

Hardfill dam is a new type of dam which has the advantages of low stress level and even stress distribution in a dam body, resulting in low demands to foundations. Based on 2D linear elastic and elasto-plastic calculations of gravity dam and Hardfill dam using finite element method (FEM), the stress distribution in a dam body and anti-sliding stabilization is analyzed on the geological faulted foundations with weak weathered rock and soft interlayers. It is concluded that Hardfill dams have better adaptability to geological faulted foundations than gravity dams and is more secure and economically sound.     

Adaptability to geological faulted foundation of Hardfill dam

Hardfill dam is a new type of dam which has the advantages of low stress level and even stress distribution in a dam body, resulting in low demands to foundations. Based on 2D linear elastic and elasto-plastic calculations of gravity dam and Hardfill dam using finite element method (FEM), the stress distribution in a dam body and anti-sliding stabilization is analyzed on the geological faulted foundations with weak weathered rock and soft interlayers. It is concluded that Hardfill dams have better adaptability to geological faulted foundations than gravity dams and is more secure and economically sound.     

面板堆石坝坝料力学性质试验研究

宜兴抽水蓄能电站初步设计为面板堆石坝。进行室内试验，研究堆石料的物理力学性质与级配，密度，泥岩含量的关系。试验结果表明，堆石料的最大干密度需用振动台试验获得，压实堆石料具有强透水性，低压缩性，破坏应变低，抗剪强度高，各料场级配石料均能够作为面板堆石坝的筑坝材料。在进行了不同级配和泥岩含量的堆石料试验基础上，统计分析了各力学参数与泥岩含量的关系。     

深水大坝裂缝修复型聚氨酯注浆材料的性能研究

为研究高聚物注浆材料在深水裂缝修复中的可行性,制备了一种双组分发泡聚氨酯注浆材料,探讨了该材料的流变性能、抗水分散性能及抗渗性能,并通过模型试验探究其在裂隙中的扩散规律.结果表明,新型聚氨酯注浆材料抗水分散性能强、流变性能优异、韧性较好、抗渗性能优良,适用于深水大坝裂缝的封堵,为形成深水大坝裂隙修复高聚物注浆成套技术及...     

Research review of the cement sand and gravel (CSG) dam

The cement sand and gravel (CSG) dam is a new style of dam that owes the advantages both of the concrete faced rock-fill dam (CRFD) and roller compacted concrete (RCC) gravity dam, because of which it has attracted much attention of experts home and abroad. At present, some researches on physic-mechanical property of CSG material and work behavior of CSG dam have been done. This paper introduces the development and characteristics of CSG dam systematically, and summarizes the progress of the study on basic tests, constitutive relation of CSG material and numerical analysis of CSG dam, in addition, indicates research and application aspect of the dam.     

白鹤滩拱坝谷幅变形预测及不同计算方法变形机制研究

中国已建成的特高拱坝如溪洛渡、锦屏一级等,在初期蓄水过程中均表现出了谷幅收缩的异常现象。而拱坝是高次超静定结构,对坝基变形尤其是不均匀变形非常敏感。从有效应力改变和岩体材料泡水弱化这一谷幅变形机制和边界施加位移这一计算手段出发,利用弹塑性有限元方法,计算并预测白鹤滩拱坝在初期蓄水过程中可能产生的谷幅变形,并分析了谷幅变形对大坝位移和应力的影响。结果表明:两种方法的计算结果相差很大;从有效应力改变和岩体材料弱化角度出发,白鹤滩拱坝两岸山体可能产生的最大谷幅收缩不大于40mm,且该谷幅变形不会很大程度上降低拱坝的整体稳定性,只是使坝体产生了新的应力集中区。而拱坝对施加边界位移具有很强的超载能力,但谷幅收缩对坝体应力的影响极小。对比发现,坝基不均匀变形是影响拱坝应力的关键因素。     

Influence of soft rock-fill material as dam embankment with central bituminous concrete membrane

This paper demonstrates the difficulties in determining the relevant material parameters for a valuation of the deformation behavior of the up- and downstream dam shell by means of an embankment dam of medium height. Laboratory as well as field tests on solid rock-fill material were performed before the beginning of construction. During the construction the properties of the available rock-fill changed from solid to soft materials. This gave rise to the necessity of adjusting the dam design of the downstream dam shoulder. Several times higher dam settlements as well as significant differential settlements between the up- and downstream dam shell were observed during construction and operation. Apart from this situation, the dam has been operated for nearly 20 years and the behavior of the water barrier has been very good.     

新型建材行业形势分析与展望

对新型墙体材料、保温隔热材料、防水密封材料等新型建筑材料的发展现状进行了分析介绍,并对新型建材及制品的发展进行了展望,同时提出了发展新型建材及制品的对策与建议,以促进建材工业的健康发展。     

Numerical analysis of a double layer rubber dam

A new rubber dam with two layers of dam bodies anchored closely into a rigid base is proposed to improve the water-retaining ability of the conventional rubber dam. Numerical studies using FLAC^2D software are conducted to analyze the behavior of the proposed double layer rubber dam. Laboratory model tests are also carried out to verify the accuracy of the numerical model. It is found that the optimal internal water head in the upstream dam normalized by its cross-sectional perimeter ranges from 0.35 to 0.45, and that in the downstream dam ranges from 0.32 to 0.40. The double layer rubber dam has optimal perimeter ratio of 0.8 and optimal anchoring distance normalized by cross-sectional perimeter of upstream dam of 0.08. For same ultimate external water head, the cross-sectional perimeter of the double layer rubber dam increased by 25.7%–49.6% than that of conventional rubber dam in different design parameters. However, the requirements of the maximum circumferential tensile strength of the upstream and downstream dams decreased by 40.8%–62.9% and 51.9%–69.6%, respectively. Assuming the material cost is determined by length and maximum circumferential tensile strength of membrane materials, the total material costs of the proposed double layer rubber dam reduce at most 82.2% than those of the conventional rubber dam in different design parameters.