【作者】 白金朋；

【导师】 彭华；

【作者基本信息】 中国地质科学院 ， 地质工程， 2013， 硕士

【摘要】 地壳应力的状态变化是引起褶皱、断裂及地震等地表变形及破坏发生的根本因素,发生在地壳表面的各种地质灾害都与地应力的作用息息相关。钻孔应变观测是将观测仪器安装在钻孔下数十米至数百米的基岩中精确的观测地层内部应力-应变状态变化,以研究分析应变异常与地质灾害的关系,这种技术是研究地壳应力状态及其变化规律的主要手段,同时也是地震前兆观测中重要的组成部分。体积式钻孔应变观测仪力学原理简明清楚,具有良好的高频特性与高灵敏度,仪器受地面观测干扰因素小,易于取得较为可靠的观测资料,在全球的应变观测仪数量中占有很大的比例。本文研究了液压式高精度体应变仪的研制过程,开展了仪器安装孔地应力绝对测量的研究工作,同时通过资料收集,研究了体应变仪观测的影响因素,分析了体应变映震能力和研究了体应变曲线的同震前兆异常,经过近两年的学习与研究,取得了以下初步进展和认识：1.TY系列高精度体积式钻孔应变仪易于装配、运输与安装,系统稳定,使用寿命长。观测精度优于1×1011ε,不作调零时,系统的动态范围达±2×101以上,超过±86dB。2.介绍了高精度体应变仪的力学、电学及其关系设计,对比分析研究了TY系列体应变仪的数据采集、放大电路、通信方式、数据传输技术压力传感器、电磁阀等仪器研制过程中选用的技术与设备：通过模拟试验,验证了该型号体应变仪的密封性和耐压性达到1000m深度安装要求,并提出了高精度体应变仪的选址规范、安装钻孔技术指标、仪器安装流程规范,研制了仪器安装过程中的水泥投放器。3.深孔空心包体地应力测量仪可用于深孔体应变仪器安装地点的应力解除测量,该仪器是一种将应变仪、应力计、电子罗盘、压力传感器、温度计等集成于一体的无电缆微型探头,该仪器不破坏所测点位钻孔环境,不影响后续仪器安装及应变观测,使用该仪器在张江应变观测孔进行了地应力测量,结果表明张江观测孔365m处地应力水平最大主应力为8.5～9.0MPa,方向为93°～96°即近EW向,与附近震源机制解获得结果基本一致。4.研究了体积式钻孔应变仪的观测影响因素。得到了体积式应变观测的固体潮公式,固体潮汐是体应变日波、半日波的主要影响因素。同时给出了钻孔体应变观测影响的气压干扰模型,推导了应变气压干扰公式及气压系数公式。降雨通过大地负载效应渗入岩体孔隙中,引起孔隙压力增加导致地壳应变变化,降雨和水位变化对体应变的影响与应变观测台站所处地区裂隙发育情况息息相关,水位变化达到一定水平后,岩体应变才会发生相应变化。5.TY系列体应变仪能清晰观测到1600格值(单位)的应变固体潮,精度优于1011ε。推导了山丹体应变仪观测台站的映震能力公式以及该台站震级与应变地震波、震中距的关系式,根据该关系式可通过应变地震波最大振幅和震中距来求地震震级,计算表明山丹体应变观测台站能够记录到地球上任意位置Ms6.5级以上的地震。研究了汶川8.0级地震和日本本州9.0级地震同震应变异常,山丹台站记录到了汶川地震明显的同震应变阶跃,而代家坝台站记录到的日本本州东海岸9.0级地震体应变异常曲线中却没有以往大震都有的应变阶跃异常,这可能是由地震发震机理不同造成的；同时日本大地震引起了代家坝观测台站固体潮日漂趋势的下凹异常。山丹和代家坝体应变台站都记录到了地震引起的周期为600～1200s的地球自由震荡。更多还原

【Abstract】 Deformation of the crust, tectonic movement within the Earth the and the varieties of geological disasters are closely associated with in-situ stress. The change of crustal stress state can cause the fault fracturing. wrinkles and even an earthquake. Borehole strainmcter observation is installed the strainmeter in the borehole which is tens to hundreds of meters underground, and then precisely monitoring the strata stress-strain state. It is a primary means to study crustal stress states, and it also plays an important part in earthquake precursor observation. The volumetric borehole strainmeters has a clear and concise mechanics, and it has a higher-frequency and sensitivity, low dependence on rock and cement status, makes it easy to obtain more reliable observational data, therefore, it occupies a large proportion of the number of strain observation instrument in the world. This paper studies how this high-precision volumetric strainmeter developed, and the work of in-situ stress measurement of the borehole which would install strainmeters is carried on in this paper, several influencing factors of volumetric strainmeters is studied through data analysis, the earthquake reflecting ability of volumetric strainmeters is analyzed. And coseismic precursory anomaly of volumetric strain curve also is studied in this paper. After nearly two years of study and research, the author has made initial progress and understanding as follows:The series of high-precision volume type borehole strainmeter which is named TY types, is easy to assemble, transport and install, this type of strainmeter has a stable system, which make it get a long serving life. Its’ obse’rvation accuracy is superior to1×10-11ε. and the dynamic range is±2×104, which is over±86dB.The mechanics designing and the relationships between mechanics and electricity is introduced, the technology of data-capture, amplifying circuit, communication method between ground and underground instrument is studied, and contrastive study of different instruments (pressure sensor. solenoid valve) is carried on. It is shown that the TY series strainmeters can work at the depth of1000meters underground through simulation experiments like encapsulation test and voltage withstand tests. The GPRS wireless network data transmission technology and network address of the primary server exchange data processing technology that this series strainmeters used is introuduced. The site selection principle, technical indicators, installation steps is studied, and a cement dispenser for installing the strainments is developed.The deep borehole hollow inclusion strain gauge in-situ stress measuring instrument and its assistive tools which were used for deep borehole in-situ stress measurement.lt integrates hollow inclusion strain gauge, strain recording apparatus and electronic compass into a micro-probe, which can be installed at predesignated position in the borehole when measuring the in-situ stress. We obtained in-situ stress data of Zhangjiang observation borehole at the deepest depth of385m underground by using this technology, the results shows the maximum principal stress direction in surveying area is near EW direction, and the values of maximum principal stresses are between8.5and9.0MPa. The minimum principal stress direction is near vertical, and the values of minimum principal stresses are near to the overburden pressure. Measurement shows that deep borehole hollow inclusion strain gauge in-situ stress measuring instrument is suitable for deep hole of3d in-situ measurement.It shows that1600grid values strain solid tidal is clearly observed by TY series volumetric strainmeters, which proved that its" accuracy is better than10-11ε. The coseismic precursory formula of Shandan volumetric strain observation station is derived. And the relationship of strain curve magnitude,the strain earthquake waves and epicentral distance is studied, according to this relationship we can obtained the earthquake epicenter when we know the information of stain seismic waves maximum amplitude and epicenter. It shows Shandan volumetric strainmeters observation station can record any earthquake over Ms6.5wherever it happen on the planet. The coseismic strain anomaly of Wenchuan8.0earthquake and Honshu, Japan9.0earthquake are studied, Shandan station recorded a significant earthquake coseismic-strain step, but train records of the east coast of Honshu Japan9.0earthquake of Daijiaba station did not have the apparent strain step phenomenon, this may be caused by different mechanisms of the earthquakes. Meanwhile, Japan earthquake caused the concave exception of solid tide day drift trends of Daijiaba observation stations. Shandan and daijiaba observation stations all recorded free oscillation curves of the earth with the cycle from600to1200s, which is caused by earthquake.更多还原