【摘要】 风化作用导致地表岩石的破碎,是泥石流固体物质的主要来源之一。研究岩石风化作用对于研究高原泥石流物源的积累效应和泥石流的形成机理具有重要意义。在高寒地区,地表岩石以物理风化为主。温度和水分的变化是物理风化作用的主要原因。该文选择青海省玉树州泥质砂岩,分6级不同含水率,分别开展了循环10次、20次、40次、60次、80次冻融试验,并对冻融岩样进行纵波波速测量、CT扫描和抗拉强度测量,横向比较岩石的风化程度。通过试验得出不同含水率条件下,随着冻融循环次数的增加,岩样的纵波波速、CT数和抗拉强度都呈减小的趋势。综合分析认为温差作用和冰劈效应在高寒地区岩石风化中的主要地质作用。在干燥条件下,温差作用更加明显。在含水条件下,温差风化和冰劈作用同时存在,相互促进。更多还原

【Abstract】 Weathering leads to broken of surface rocks,and is one of the main sources of the solid material of debris flow.The research on rocks weathering has important theoretical significance to the study on the solid material cumulative effects and the formation mechanism of debris flow.In cold areas,rocks weather mainly in physical style because of the changes in temperature and moisture.Argillaceous sandstone in Yushu in Qinghai Province is selected and divided into of six different water contents for freeze-thaw test.The freeze-thaw cycle time is designed to be 10 times,20 times,40 times,60 times and 80 times.Longitudinal wave velocity measurement,CT scans and tensile strength measurements are then done on all freezing and thawing rock samples to compare the degree of weathering of rocks in different test condition.It is found that rock samples longitudinal wave velocity,CT number and tensile strength are decreasing with the increasing of freeze-thaw cycle times.Comprehensive analysis results show that the temperature difference and ice split effect are the main geological actions in the alpine region.Under dry conditions,temperature effects become more pronounced.Under aqueous conditions,temperature difference and ice split weathering effects exist and mutually reinforcing.更多还原