单轴向拉伸实验晶粒组构的变化

采用实验室制备的具有随机取向的细晶粒多晶冰 ,在温度为 - 3 .0± 0 .0 5℃、初始八面体剪应力为 0 .2 MPa和 0 .3 MPa下 ,对六个样品进行了单轴向拉伸实验。对应于八面体剪应力为0 .2 MPa的一次实验 ,最小应变率为 2 .6× 1 0 - 8s- 1;对应于八面体剪应力为 0 .3 MPa的其余五次实验 ,最小应变率平均值为 8.6× 1 0 - 8s- 1。六次实验最小应变率均出现在总八面体剪应变为1 .1～ 1 .6 %之间。晶粒 c轴组构随总应变增大向大环型发展 ,最终形成以组构平均半角趋于稳定在 6 5度左右的大环型组构 ,但在总八面体剪应变达 2 0 %之前 ,可能受组构图本身几何性质影响 ,组构平均半角随应变增加反而减小。对比压缩实验结果 ,拉伸实验最小应变率值与同等条件下压缩实验得到的最小应变率值一致 ,但最小应变率出现时对应的总应变稍大 ,c轴组构转变所需的总应变则更大。     

新疆强震的钻孔应变临震前兆（二）

临震预报是地震预测预报最难之点。本文就1987年1月24日乌什6.4级强震的钻孔应变临震前兆变化进行探讨,并用数据处理方法处理资料,给出了乌什地震前应变异常清楚可信的结果。     

振动沉管灌注桩施工技术

混凝土灌注桩基础施工方法之一的振动沉管灌注桩施工技术具有多方面优越性,在某些软弱地层地基处理中发挥越来越大作用。本文以这一施工技术为要求,从设备选择,施工地层,沉管,灌注混凝土和拔管,振动沉管应注意的问题等作了较详细阐述。     

八方山多金属矿床控矿构造变形机制研究

陕西凤县八方山铜铅锌多金属矿床为一层控矿床,其后生热液改造富集作用主要受构造控制.区内主体构造为一短轴背科,产于背斜中的环状层滑断层严格控制了矿体的展布.应用构造解析、有限应变分析、显微组构分析等方法对该背斜及其次级构造进行研究,结果表明该区构造为多期变形(至少二级韧性变形和二期脆性变形)的产物,矿化富集受前三期变形控矿.     

北京西山北岭向斜卷入区构造应变场的初步研究

本文通过系统的有限应变测量,用主应变等值线及主应变方向迹线网络的形式,建立了北京西山北岭向斜卷入区的构造应变场;并通过宏观构造分析,证明这个应变场是合应变场,反映四期构动变动。在构造叠加部位,主应变迹线显示异常形态。本文还对应变场的建立方法作了讨论。     

从南通地形变等变化探讨地震短临预报的可能途径

1990年2月10日常熟——太仓5.l级地震前,南通等地形变等前兆手段异常明显。震例资料揭示,此次地震敏感部位的形变等前兆变化可区分出阶段性。据此作者探讨了形变短临地震预报的可能途径。     

A visco-elastoplastic model for fault rocks and its application to earthquake research

In the light of the rheological properties of crustal rocks and some features of earthquakes, a rheological model for fault rocks is suggested in the paper and the possibility of applying the suggested model to the study of earthquake mechanism is discussed. The results show that it is reasonable to take the suggested model as a physical simplification of fault rocks and to apply it to the numerical calculation and simulation of 2-D problems. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 129–136, 1992.     

岩爆烈度分级问题

在指出前人岩爆烈度划分所存在主要问题的基础上,本文提出了岩爆烈度新的分级原则、依据,以及新的烈度分级;同时总结了岩爆防治的有关措施。     

天然淡水冰单轴压缩强度及其温度和应变率效应

本文报道了在不同温度和不同应变率下天然淡水冰单轴压缩强度的实验结果。指出S—l型柱状晶粒冰的压缩强度随着温度的降低而增加,极限压缩强度在应变率为10~(-4)S(-1)时有一个最大值。本实验的应变率范围是10~(-5)—10~0s~(-1)。10~(-1)—10~0s~(-1)的应变率范围是在冲击速度lm/s左右的实验条件下获得的,这个速度接近于浮冰与海上结构物相撞的情况。以本实验为基础,有希望发展对海冰的实验技术。     

Ri-μi/μm-Ci dependent oblateness of deformed pebbles in the Baraitha conglomerate,Central India and tectonic implications

Strain analysis of the Baraitha conglomerate is attempted by direct measurements on extracted pebbles and by micrometric analysis. The overall deformation is of flattening type, with thek value lower by more than half in the matrix than in the pebbles. The viscosity contrast between pebbles and matrix (μ _i/μ_m) is in the ratio of 2:1 and the bulk deformation appears to be strongly controlled by C_i (concentration of pebbles expressed as percentage). The total shortening (≃35%) in the Baraitha conglomerate is comparable with the shortening accomplished in the folding of the overlying Bijawar Group volcanosedimentary sequence. The bulk strain axesX _t, Y_t andZ _t, as determined from the analysis of the deformed conglomerate, are unsymmetrically oriented with reference to folds formed by oblique flexural-slip with neitherX _t norY _tcoincident with the fold hinges. The lack of transection of folds by cleavage again suggests flattening deformation. The extension in theY _tdirection is greater in the matrix than in the pebbles.