共查询到20条相似文献,搜索用时 62 毫秒
1.
《中国农村水利水电》2015,(2)
为了解决香山拱坝的裂缝问题,在介绍香山拱坝裂缝基本情况的基础上,从设计、施工、坝体溶蚀等方面对裂缝产生的原因进行了分析,并对拱坝应力进行计算验证,提出了加固处理措施,同时,对拱坝的设计提出了建议,进行了有益的探索。 相似文献
2.
浆砌石坝漏水在水库中比较普遍。针对灵湖水库浆砌石坝的漏水问题,在分析漏水原因的基础上,从三个治理方案中选择出用环氧材料填塞、涂抹裂缝和块石座浆缝方案,并经过多次现场试验,选定了两种配合比。最后,介绍了施工技术和注意事项及治漏效果。 相似文献
3.
郑建青 《中国农村水利水电》2000,(10):35-37
为了解决长白桥拱坝裂缝问题,通过对拱坝运行和裂缝产生时各工况进行应力复核计算,找出了裂缝产生的原因是温度荷载、低水位运行和拱坝形体不合理,并确定了杜绝裂缝危害的具体方法。 相似文献
4.
林庆洪 《中国农村水利水电》1999,(9):25-27
仙游县蒋隔水库蓄水后,大坝右岸导流洞封堵段下游出现漏水,随着库水位升高,漏水量也相应增大,从渗流、滴流、线流至射流,严重影响山体稳定和危及建筑物安全。经专家观察分析:右岸突出部分山脊单薄,受三组断层结构影响,岩石破碎,裂隙发育,是漏水的主要原因。在水库蓄水情况下,采取造孔灌浆提高山体防渗性,有效地堵塞漏水通道的方法,经过13年的水库正常运行观测,其效果良好。 相似文献
5.
6.
余际可 《中国农村水利水电》1991,(11)
拱坝是一种经济而安全的坝型,我省15m高以上的拱坝有60多座尚无失事记录,其中除6座(东江、风滩、欧阳海、花木桥、半江、长潭河)为砼坝外,其余均为砌石拱坝。若计入15m高以下的拱坝,仅湘西自治州一地就有154座,占全省总数2/3。但我省众多的砌石拱坝中,出现裂缝事故的不在少数,较大的有大庸茅溪、保靖卡棚、双峰板冲、慈利索溪峪、涟源大江口等。在国内,砌石拱坝出现裂缝的更是屡见不鲜,以致有“十拱九裂”之说。已出现的裂缝有水平裂缝及竖向裂缝,但竖向裂缝发生较为频繁,原因也更为复杂,故本文以竖向裂缝特别是温度裂缝为论述重点。 相似文献
7.
李钒 《中国农村水利水电》2006,(7):115-116
坝体裂缝是土坝常遇到的工程问题,而产生坝体裂缝的原因是多种多样的。本文以茜坑水库坝体裂缝调查分析为例,介绍了进行坝体裂缝调查的内容,分析土坝裂缝产生机理。文中首先利用排除法,分析茜坑水库坝体裂缝的可能成因,之后对地质条件、筑坝材料、水文、气象、运行维护等种种可能成因,逐项进行分析,最终得出茜坑水库坝体裂缝产生的原因。 相似文献
8.
小型水库涵洞(管)漏水处理与反压灌浆 总被引:1,自引:0,他引:1
廖德标 《中国农村水利水电》1996,(11):35-37
水库工程的涵洞(管)是水利枢纽主要组成部分,是工程能否正常运行的关键部位。涵洞(管)的老化失修而导致漏水,严重影响工程的安全运行。涵洞漏水主要有沿涵洞(管)壁的纵向漏水,穿过涵洞(管)壁的横向漏水。以实例就涵管的漏水处理、反压灌浆处理效果进行了总结、分析。 相似文献
9.
胡学良 《中国农村水利水电》1992,(3)
由于有害离子侵蚀,混凝土碳化,钢筋锈蚀等方面原因,致使渡槽排架混凝土产生裂缝、剥落,严重危及着渡槽的安全运行。因此寻找一种科学、实用、简便的处理裂缝的方法,是当前渡槽老化损坏处理的一个重要课题。针对韶山灌区山枣渡槽排架裂缝的处理实例,提出一种 NUS 水泥砂浆处理渡槽排架裂缝的新方法。用该法处理后的渡槽排架,经运行观测,效果较好。 相似文献
10.
11.
12.
13.
14.
15.
《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
16.
17.
感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
18.
19.
The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献
20.
从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献