【作者】 周平；

【导师】 杨晓松；

【作者基本信息】 中国地震局地质研究所 ， 固体地球物理学， 2006， 硕士

【摘要】 高温高压实验研究作为现代地球物理学研究的一项重要内容,是探索地球深部物质和地球内部奥秘的一个重要手段。它通过观测岩石或矿物在原位条件下的物理特征,为地球物理探测成果解释提供非常重要的实验约束。固体传压介质活塞圆筒式实验装置是一种常见的大样品腔实验装置,它能够模拟较为复杂的地球深部环境。本实验室采用的便是此类装置,其设计实验温度和压力上限分别为1200℃和1.5GPa。近几年来,本实验室经历了一系列的系统改造与升级,增加了新的样品腔,提高了数据采集精度,完善了实验控制程序。升级后的高温高压实验系统内部,温度和压力均是未知的,因此,需要设计实验对其进行准确标定。实验系统的标定主要包括三个方面的内容:位移标定、温度标定和压力标定。1.位移标定。在实验设计与装配上,选择了天然叶腊石作为固体传压介质。实验结果显示,天然叶蜡石的传压效果良好,它与实验样品构成样品腔内部两大“软物质”,是实验变形的主要承载体。因此,将实验样品用刚玉代替,标定出叶腊石在不同压力下的变形压缩量,并以此作为参照值计算样品在相应条件下的压缩情况,校正弹性波波速。叶腊石压缩量实验结果显示,天然叶腊石的液压（L）-位移（D）曲线可分为两段:第一段,叶腊石裂隙和装样缝隙闭合与受压变形段（L≤2.0MPa）。液压值与叶腊石位移量之间的关系为二次曲线: D=-90.55L²+881.27L-4529.76,R²=0.9994;第二段,叶腊石压缩本征位移段（L>2.0MPa）。液压值与叶腊石位移量之间为良好的线性关系: D=400.34L-3905.04,R²=0.9998。2.温度标定。本实验装置属大样品腔类,样品腔内部的温度存在差异,因而需要对其进行标定。为了了解样品上温度的分布状态,在样品腔内部的三个不同位置,分别放置了三根相同的热电偶进行同步测量（样品径向中心边缘、样品中心和样品纵向顶端）。实验结果显示,在样品径向中心边缘（S点）,温度最高;样品中心（C点）次之,样品顶端（T点）最低。在样品内部,径向温度差异较小,而纵向温度差异较大。根据温度梯度测量实验结果,计算并拟合得到了样品内部的平均温度（Tmean）与边缘控制温度（Ts）之间良好的线性关系式: T_mean=0.96879Ts-0.66168,R²=0.998。3.压力标定。前人的研究表明,高温高压实验装置的压力标定方法有多种,最常见的有相变法和高压熔融曲线法等。其中,石英α-β相变法是一种较为特殊的方法。石英发更多还原

【Abstract】 As a significant branch of modern geophysics, experimental research at high temperatures and high pressures is an important approach to explore substance deep in the earth and to discover secret in the earth interior. Measuring the physical characteristics of rocks or minerals in situ, petrophysical experiments can provide effective constraints on the interpretation of geophysical surveys.The piston-cylinder type device with solid confining pressure medium, by which some complex settings deep in earth could be simulated, is popular in experiments on natural rock samples. In the laboratory of petrophysics under the high temperature and high pressure, the upper limits of pressure and temperature of this type of device are 1.5 GPa and 1200℃, respectively. In recent years, the lab has been changed and advanced a lot. The precision of data collection as well as the experimental control program have been improved. Furthermore new sample chambers are used in which the pressure loss, the temperature distribution and displacement are unknown. Therefore, experiments should be prepared and carried out for the experimental system calibration.The experimental system calibration includes three aspects: displacement calibration, temperature calibration and pressure calibration.1. Displacement calibration. In the experimental design and assemblage, natural pyrophylite has been used as the solid confining pressure medium. The experimental results have shown that natural pyrophylite is well fit for pressure confining. The two soft materials, pyrophylite and the experimental sample, are the main body of experimental compression bearing the pressure loaded. Thus, the experiment was carried out with corundum as the sample to determine the displacements of pyrophylite assembly under pressure. The values could be used as a reference to estimate the compression or length of the experimental sample in future experiments, and thus revise the velocity preliminarily.The experimental results show that the curve of load pressure (L) and displacement (D) can be divided into two segments:One is the cranny closure and pressure-deduced compression segment with the load pressure upper limit 2.0MPa. The curve is a conic, and its expression is: D=-90.55L~2+881.27L-4529.76,R~2=0.9994.Another is the pressure-deduced compression segment with the load pressure over 2.0MPa.The curve is an excellent line, and its expression is:更多还原