辽宁沿海灌区衬砌渠道防冻胀设计研究

发布时间：2018-07-03 01:27

  本文选题：辽宁沿海灌区 + 抗冻胀　； 参考：《沈阳农业大学》2017年硕士论文

【摘要】：相关试验资料表明,采用渠道防渗措施,水的渗漏损失可减少70%～90%,我国渠道防渗主要采用混凝土渠道防渗。在北方由于气候等原因,混凝土防渗渠道有冻胀破坏现象,情况较为严重,而辽宁省水田灌区大部分分布在沿海区域,因此研究辽宁沿海灌区渠道的防冻胀破坏,对提高工程耐久性和辽宁省沿海地区的水稻种植产量并更有效地遏制灌溉用水的浪费现象具有重要意义。首先选取辽宁省内距海岸线100km内的灌区,对其地下水位、离海岸线距离、设计灌溉面积三项指标进行模糊聚类分析,得到离海岸线距离60km,地下水位在3m以下的灌区为沿海灌区。为了研究辽宁省沿海灌区衬砌渠道的防冻胀,根据土质、地下水位、气温相似性,将沿海灌区划分为四个片区,其中葫芦岛与锦州为一个片区,丹东与大连为一个片区,营口与盘锦分别为一个区,并选取典型灌区为海滨灌区、大洼灌区、营口灌区、红旗水库灌区。由于本文中最大切应力与冻胀量的计算需要选取与土质有关的参数,所以采集了典型灌区的土样,经过比重试验、颗粒分析试验、界限含水率试验,对其进行土质命名。然后选取辽宁省沿海灌区衬砌渠道的典型断面形式:底板宽0.8m,渠深0.8m,边坡1:1.25,并根据王正中等建立的梯形混凝土衬砌渠道力学模型公式,以及抗裂条件公式σ0/Ec≤εt计算可知,采用C25混凝土,衬砌板厚为10cm,可满足抗裂要求。又根据辽宁省水利科学研究所王希尧等人推出的冻胀量公式h=f Zd,和苯板保温厚度选取的公式δx=αwαλx(R0-δc/λc),得到辽宁省沿海灌区衬砌渠道适合采用10cm厚的苯板结构,可以满足抗冻胀要求。最后为了验证以上计算的合理性,以海滨灌区为项目试点,建立了 12种不同结构形式的衬砌,并实测了 2015年12月至2016年3月期间的渠基土 40cm、80cm的地温、基土冻深和基土冻胀量3个指标,通过分析对比发现当断面形式为底板宽0.8m,渠深0.8m,边坡1:1.25的衬砌渠道时,可选用C25混凝土,板厚10cm,铺设10cm厚苯板结构,能够有效的解决辽宁沿海灌区的衬砌冻胀问题。
[Abstract]:The relevant experimental data show that the leakage loss of water can be reduced by 70% 90% by adopting canal seepage control measures. In our country, concrete channel is mainly used to prevent seepage. In northern China, due to climate and other reasons, concrete seepage prevention channels have frost heaving damage phenomenon, and the situation is relatively serious. However, most of the paddy field irrigation areas in Liaoning Province are distributed in coastal areas, so the anti-frost heaving damage of the canal in Liaoning coastal irrigation area is studied. It is of great significance to improve the durability of the project and the yield of rice planting in the coastal areas of Liaoning Province and to curb the waste of irrigation water more effectively. Firstly, three indexes of groundwater level, distance from shoreline and designed irrigation area are analyzed by fuzzy cluster analysis. The irrigation area with water level below 3m is the coastal irrigation area, which is 60km from the coastline. In order to study the antifreeze expansion of lining canal in coastal irrigation area of Liaoning Province, according to the similarity of soil quality, groundwater level and temperature, the coastal irrigation area is divided into four regions, one of which is Huludao and Jinzhou, the other is Dandong and Dalian. Yingkou and Panjin are one area, and the typical irrigation areas are seaside irrigation area, Dawa irrigation district, Yingkou irrigation district and Hongqi reservoir irrigation area. Because the calculation of maximum shear stress and frost heave in this paper needs to select the parameters related to soil quality, soil samples from typical irrigation areas are collected and named after specific gravity test, particle analysis test and limit moisture content test. Then the typical section form of lining canal in coastal irrigation area of Liaoning Province is selected: base plate width 0.8m, channel depth 0.8m, slope 1: 1.25. according to the mechanical model formula of trapezoidal concrete lining canal established by Wang Zhengzhong, and the formula of anti-crack condition 蟽 _ 0% EC 鈮，

本文编号：2091758