某电厂灰场子坝加高工程试验方案简述

以某电厂灰场子坝加高工程为背景,讲述了该灰场库区内现场碾压试验的工作内容,经过试验得出满足设计干密度要求的铺灰厚度、碾压方式及压实机械的组合方式等施工数据,以期指导实际工作。     

贮灰场防渗处理土工膜施工方法探讨

陈述了贮灰场坝脚以下 ,水中土工膜铺设方法和坝脚以上坡面土工膜铺设的做法     

粉煤灰坝模型试验研究

以湖南省耒阳电厂粉煤灰坝的加高加固工程为研究背景,采用大型液压伺服式振动台作为试验手段,分别对高程为170,180,230 m的灰坝模型进行了动力特性试验研究,并进行了计算验证。同时,对采用3种不同灰渣拌合料加高的180 m高程灰坝模型进行了动力特性评价并认为其对灰坝的整体动力特性没有太大的影响。试验结果表明,灰坝的自振频率是随着激振加速度的增大和坝体的加高而降低的;坝顶加速度放大倍率也是随激振加速度的增大而降低的;两者在有干滩工况下普遍大于无干滩工况。     

粉煤灰筑子坝新技术应用

在姚孟电厂程寨沟灰场加高工程中，利用粉煤灰筑坝，取得了成功。本文介绍了粉煤灰辗压坝一系列参数和结构措施，以及在自然沉积的粉煤灰中设置垂直集渗井的新工艺。     

长沙电厂干灰场环保优化设计

针对灰渣贮放引起的主要环境问题,结合工程实例,采用一系列的新材料和新方法,对临江的大堤、灰坝进行防渗、加固、加高处理,从而解决了灰场环保与灰场渗漏等设计优化问题。     

山谷型灰场深化设计与施工的几点思考

介绍了“山谷型”灰场选址、初级坝建设中深化设计与施工要点,并阐述了子坝加高中的深化设计与施工,最后总结了贮灰场工程建设与运行管理中的环境影响因素以及采取的环境控制措施,从而证实了深化设计与施工在实际工程应用中的重要作用。     

贮灰场的地震反应分析及抗震加固

燃煤火电厂湿法贮灰场的灰渣沉积层往往处于饱和松软状态,难以在其上建造子坝,且灰渣层在地震作用下极易发生液化,危及灰坝安全。笔者结合某些电厂贮灰场的子坝加高工程,在室内外试验的基础上,用有效应力的动力分析法计算了地震作用下贮灰场的动力反应,并提出了抗震加固措施。为类似贮灰场的抗震分析与加固指出了一条有效的途径。     

向阳沟贮灰场四级子坝加高方案论证

目前,灰场已接近三级子坝贮灰限制高程,为满足电厂后续贮灰的要求,拟在三级子坝坝前沉积灰上采用灰渣作为筑坝材料进行四级子坝加高。为保证安全,进行四级子坝加高时需进行子坝加高方案论证。根据试验及计算分析结果可知,对于三级子坝,在正常工况和可能出现最不利的工况条件下,三级子坝下游边坡的稳定性满足有关规范要求,可以进行子坝加高。四级子坝的加高方案采用坝高为5.0m,下游边坡坡度不陡于1:3.5,上游坡坡度不陡于1:2.5,坝顶宽度5.0m,子坝的筑坝材料可采用库内沉积的粉煤灰。     

复合土工膜在青岗峡水电站坝前防渗中的应用

以复合土工膜中的“两布一膜”在青岗峡水电站坝前防渗中的使用情况，介绍了其应用、施工方法及注意事项。工程实践表明，该技术造价低、施工工艺简单、施工速度快、无毒且防渗性能好，具有推广价值。     

振冲碎石桩在加固灰坝地基工程中的应用

以前根据电厂容量灰场往往一次建成，一般灰坝为不透水坝，由于排渗系统不够完善，导致库内灰渣沉积层始终处于饱和状态，给后考虑加高带来了许多困难。本文介绍了振冲碎石桩在加固谏壁电厂，景德镇电厂两个贮灰场工程中取得成功的实例，并对设计，施工中应该注意的问题提出了自己的观点。     

加筋粉煤灰的工程力学性质试验研究

通过含钙量较高的粉煤灰与普通粉煤灰混合,进行了相关的工程力学性质试验,试验结果表明：粉煤灰混合料的最优含水率、最大干密度与高钙粉煤灰的掺加比例线性相关;粉煤灰混合料的无侧限抗压强度能够满足路基工程的要求,且具有一定的抗拉能力;养生后土工网对粉煤灰的内摩阻力迅速增大,界面处的似摩擦系数增大。     

Shear strength response of reinforced pond ash

Reinforced pond ash is a composite material, which can be used as an alternative construction material in the field of geotechnical engineering. To study the shear strength response of reinforced pond ash, a series of unconsolidated undrained (UU) triaxial test has been conducted on both unreinforced and reinforced pond ash. In the present investigation the effects of confining pressure (σ₃), number of geotextile layers (N), and types of geotextiles on shear strength response of pond ash are studied. The results demonstrate that normal stress at failure (σ_1f) increases with increase in confining pressure. The rate of increase of normal stress at failure (σ_1f) is maximum for three layers of reinforcement, while the corresponding percentage increase in σ_1f is around (103%), when the number of geotextile layers increases from two layers to three layers of reinforcement. With increase in confining pressure the increment in normal stress at failure, Δσ increases and attains a peak value at a certain confining pressure (threshold value) after that Δσ becomes more or less constant. The threshold value of confining pressure depends on N, dry unit weight (γ_d) of pond ash, type of geotextile, and also type of pond ash.     

Quantitative assessment of the shoreline protection performance of geotextile sandbags at an in-situ coastal experimental station

The coast of China is periodically impacted by tropical cyclones and storm surges, and has experienced significant coastal erosion problems. Traditional “hard engineering” coastal protection measures used to protect Chinese sandy coasts from storm erosion are found to be expensive and less environmental and even make sandy beach disappearing. In this study, geotextile system as a more flexible material was developed and qualitatively compared with the traditional coastal protection measures. An in-situ permanent revetment was applied with durable geotextile sandbags on the coast of Chudao in China from October 2018 to October 2020, and it was designed for three different testing segments to optimize the stability and construction cost of geotextile sandbags. The field surveys were carried out to collect the in-situ data on beach profiles, wave dynamics, material durability, and sandbag revetment stability. In analyzing the two-year field data collected, it is found that the testing segment-2 wrapped with sheet of plastic geogrids is the most effective of the three testing segments in terms of their coat, structural stability and material durability, and that both the slope of the seabed and the design thickness of geotextile sandbag are the dominate factors responsible for the failure of sandbag structures.     

Unconfined compressive strength of fly ash reinforced with jute geotextiles

A series of unconfined compressive strength (UCS) tests have been conducted on unreinforced fly ash as well as fly ash reinforced with jute geotextiles. The effects of different governing parameters viz., degree of saturation, size of samples, number of jute geotextile layers and age of sample on UCS have been studied. From the test results it is found that the values of UCS are maximum at degree of saturation of 70–75%. The effect of sample size on the values of UCS for unreinforced fly ash is insignificant, whereas with increase in diameter of sample, values of UCS increase in case of reinforced fly ash. With increase in number of jute geotextile layers for reinforced fly ash samples, values of UCS increase and maximum enhancement is found to be around 525% with 4 layers of reinforcement. A non-linear power model has been developed to estimate unconfined compressive strength (UCS_R) of fly ash reinforced with jute geotextiles in terms of unconfined compressive strength (UCS_UR) of unreinforced fly ash and number of layers of reinforcement (N).     

对我国软基上加筋堤坝设计的一些意见

软基上加筋堤坝工程的设计是一个重要和经常遇到的问题,但国内至今尚未有一个专门的、系统的设计规范。在国内若干土工合成材料的工程行业规范中,对此问题有所涉及,但大都比较简单,而且考虑土工合成材料的性能和加筋工程的特点不够深入和全面,这种现状应当改进。本文对比了国外和国内的有关规范的差别,指出了改善我国规范的一些设想,供有关方面参考。     

海军某工程水下土工布铺设工艺

土工布铺设为海军某工程堤身首道工序，该工程位于开敞、无遮掩海域，施工难度较大。本工程采用小锚牵引土工布边铺设边压载的施工工艺，对以后类似无掩护水域土工布铺设施工有一定的参考价值。     

土工织物加筋堤坝软基的非线性分析

通过非线性有限单元法分析了堤坝下软基土工织物的加筋效果,土与土工织物的界面强度对加筋效果的影响,多层土工织物的加筋效果等问题,得出了最优加筋层数、加筋垫层应力扩散效果等一系列对工程设计有用的结论