文章结合梅子箐水库扩建工程高涧构水库昔格达土碾压试验,阐述了土石坝填筑碾压试验目的、方法及参数组合,确定了昔格达土作为筑坝材料的施工参数,为昔格达土筑坝填筑提供施工技术依据.

文章介绍了攀枝花市西区梅子箐水库扩建工程三洞桥水库主坝坝址、坝轴线、坝型的选择过程,根据坝址地形、地质条件和当地建筑材料情况,着重介绍了碾压心墙土石坝与混凝土重力坝中的四种材料坝进行详细比较并择优选择的过程,为类似工程坝型选择提供参考依据.

昔格达地层具有成岩低、结构构造不均一,富含粘粒及粘土矿物,压缩性较强,遇水易软化,脱水崩解等特点.通过对昔格达泥岩夹粉砂岩的物理性质分析及工程特性试验研究,结果表明:①昔格达泥岩夹粉砂岩土料的可溶盐和有机质含量以及pH值都满足规范要求,且土料为非分散性、非膨胀土,渗透系数小于10-4 cm/s,满足规范对均质坝土料的质量技术要求;②昔格达土在天然含水率下易压实,且具有较高的强度和中等压缩性,可以作为均质坝的筑坝材料.

自密实堆石混凝土在水利工程中的应用是水利工程技术、工艺的重大突破.文中以三洞桥水库大坝为例,阐述了自密实混凝土的性能及在大坝工程中对原材料的要求及施工工艺.

昔格达地层具有成岩低、结构构造不均一,富含黏粒及黏土矿物,压缩性较强,遇水易软化,脱水崩解等特点.通过对昔格达土防渗料的物理性质分析及工程特性试验研究,结果表明昔格达土料的可溶盐和有机质含量以及PH值都满足规范要求,且其为非分散性、非膨胀土,渗透系数小于10-5 cm/s,满足规范对防渗土料的质量技术要求;昔格达土为中等压缩性土,其抗剪强度参数与一般黏性土相当,能够作为坝体的防渗土料.

The seepage through earth dams is the main reason of dam destruction.The steady seepage through earth dams was analyzed with the finite element of AutoBank,and using automatic meshing technology,with overlap method adopted to calculate the free water surface site(saturation line),in order to solve the problem of earth dam seepage flow stability.It provided great convenience for water conservancy and hydropower engineering and technical personnel to calculate problems of earth dam seepage.

混凝土是一种非均质的多相复合材料,内部存在着孔隙、微裂纹等结构,压力水在混凝土内渗流的过程会不同程度的使混凝土的微观结构发生改变,造成损伤；本文从理论方面分析了水在混凝土中的迁移机理、混凝土中的孔隙特性及其影响混凝土渗透性的主要因素和水对混凝土力学性质的影响,并分析了在渗透孔隙水压作用下混凝土的损伤机理.分析表明:混凝土中的孔结构对混凝土的渗透性有重要影响,其中的连通孔隙是孔隙水渗透的主要途径,且孔隙水对混凝土的力学性质有显著影响,在孔隙水压作用下,孔隙水产生水力劈裂作用,使混凝土损伤,甚至破坏.

In order to simulate work environment of high dam concrete and effects on the mechanical propertiesof concrete due to high seepage pore water pressure, standard concrete samples are immersed into a high water pressure container and high hydraulic gradient is produced in testing samples. The concrete mechanics and physical properties studied in the paper are included strength, young＇s modulus, water content and wave velocity. The effects due to different water pressure in the container （concrete pore water pressure）, time, concrete grade and aggregate maximal grain size are considered in experiments. Experimental scheme is designed by an orthogonal experiment design method, thusly, 28 groups of experiments for the studying effect of compressive strength, water content and wave velocity, 9 groups for tensile strength are obtained. The study shows that the lost rates of concrete compressive and tensile strength, young＇s modulus are gradually increased with the increase of pore water pressure. The significance test shows that pore water pressure, grain size and concrete grade are significance to compressive strength. Under same pore water pressure, the lost rates are increased with increase of grain size and reduction of concrete strength. The water content relates with pore water pressure, and concrete grade. The water content of sample is increased with increase of time and reduction of concrete strength. The wave velocity of concrete sample shows a fluctuation character with increase of pore water pressure.

混凝土内存在着孔隙、微裂纹等结构,压力水在混凝土内渗流的过程会不同程度使混凝土的微观结构发生改变,造成损伤,使其强度降低.对混凝土标准立方体试件外部施加压力水头,并充分考虑压力水在混凝土内的运动时间,让其在压力水中静置一定时间,使其充分发生渗透破坏,由此来研究混凝土不同渗流时间内、不同孔隙水压对混凝土抗压强度的影响规律.试验结果表明:在孔隙水压的作用下,混凝土抗压强度有所降低,并随着孔隙水压的增加强度逐渐降低;在未达到恒定渗流前,随着外围水压作用时间延长,混凝土强度仍会下降.