干湿循环和化学腐蚀共同作用下单裂隙非贯通试样力学特征的试验研究

发布时间：2018-02-25 08:00

本文关键词： 岩石力学裂隙岩体化学腐蚀干湿循环力学特征破坏特征　出处：《水利学报》2016年12期 　论文类型：期刊论文

【摘要】：以水库库岸边坡消落带节理岩体的实际赋存环境为背景,采用在类岩石材料中预制裂隙的方法来模拟节理岩体,通过干湿循环试验的方法,研究了裂隙试样在酸性Na_2SO_4溶液、中性Na_2SO_4溶液和碱性NaOH溶液中浸泡并经历干湿循环作用后的力学特性和破坏特征,分析了浸泡在不同化学溶液中的裂隙试样在经历不同干湿循环作用后其力学特征的变化规律。研究结果表明:自然及不同化学溶液下裂隙试样的峰值强度和弹性模量随着裂隙倾角的增加均呈现出先减小后增大的变化规律。不同化学溶液和干湿循环共同作用下裂隙试样的劣化程度逐渐加剧,其峰值强度和弹性模量随干湿循环次数的劣化规律基本一致,但不同裂隙倾角下其劣化程度却存在一定的差异,其中裂隙倾角为45°时,试样的劣化程度最大,90°和30°时居中,而60°和0°时最小。酸性化学溶液加剧了裂隙试样的干湿损伤劣化程度,而碱性化学溶液对裂隙试样却存在一定的抑制作用。完整试样和裂隙倾角为90°试样的破坏特征基本相似,为张拉破坏模式;0°时裂隙试样呈现为"H"型的张拉破坏模式;在30°和45°时其呈现出张剪混合破坏;60°时为剪切破坏。
[Abstract]:Under the background of the actual occurrence environment of jointed rock mass in the slope and drop zone of reservoir bank, the method of prefabricating fractures in rock-like materials is used to simulate the jointed rock mass. By means of dry and wet cycle test, the fracture specimen in acid Na_2SO_4 solution is studied. Mechanical properties and failure characteristics of neutral Na_2SO_4 solution and alkaline NaOH solution soaked in dry and wet cycle. The variation of mechanical characteristics of fractured specimens immersed in different chemical solutions after different dry and wet cycles was analyzed. The results showed that the peak strength and elasticity of fractured specimens were obtained under natural and different chemical solutions. With the increase of fracture dip angle, the modulus showed a change law of decreasing first and then increasing. The deterioration degree of fracture specimen increased gradually under the combined action of different chemical solution and dry and wet cycle. The peak strength and modulus of elasticity are basically the same with the number of dry and wet cycles, but there are some differences in the deterioration degree of the samples under different fracture inclination angles. When the crack inclination angle is 45 掳, the maximum deterioration degree of the specimen is 90 掳and 30 掳, respectively. But at 60 掳and 0 掳, the acid chemical solution aggravated the degree of dry and wet damage deterioration of fracture specimen, while alkaline chemical solution inhibited fracture specimen to some extent. The failure characteristics of intact sample and 90 掳fracture sample were similar. The fracture specimen shows "H" tensile failure mode at 0 掳and shear failure at 30 掳and 45 掳at 60 掳.
【作者单位】：西安理工大学土木建筑工程学院;西安理工大学岩土工程研究所;
【基金】：国家自然科学基金项目(51269024,11302167) 陕西省教育厅自然科学专项(2013JK0609)
【分类号】：TV223

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