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1.
石兆宏  马丽霞 《地下水》2014,(5):100-101
研究了易门地震前兆观测井数字化水位水温观测资料对2004年12月26日印尼8.7级、2008年5月12日汶川8.0级和2011年3月11日日本9.0级大震同震响应特征,探讨其同震响应机理,给出水位水温同震响应的合理解释。表明易门井水位水温同震变化总是水位震荡下降—迅速恢复、水温迅速下降—缓慢恢复,形态相似。与观测井所在的地质构造、井深以及探头深度密切相关。  相似文献   

2.
基于中国大陆地下流体台网井水温度数字化观测数据,本文对比分析了2008年5月12日汶川8.0级地震与2004年12月26日印度尼西亚苏门答腊8.7级地震引起的水温同震响应特征。结果表明,地震能引起井水温度发生同震响应,而井水温度同震响应特征可能主要与井孔本身的水文地质条件和区域构造环境有关。同时,根据水位同震响应资料和前人的研究结果,本文对水温同震响应的机理进行了探讨,认为在地震波动力加载作用下,井-含水层系统原有状态发生改变,很多因素可以引起井水温度发生变化,例如井孔垂直方向上因对流和水动力弥散引起的温度变化、井-含水层系统水平方向上水流状态改变引起的温度变化、井孔水由于气泡脱逸引起的温度变化、井孔水与井壁及水温探头摩擦引起的温度变化等,因而,合理考虑以上因素,才能有效分析井水温度同震响应的机理。  相似文献   

3.
在2004年12月26日印尼苏门答腊M_s8.7级地震同震水位、水温变化类型的对比分类中,发现出相当具有规律性的一类变化类型:在某些观测井当水位出现振荡(水震波)的时候,同井水温绝大多数会有个几十分钟到数小时的从下降到恢复的过程。为此笔者又收集了其中的典型变化观测井,北京良乡井和河北唐山矿井2001年数字化以来30多次不同远场大震水位、水温的同震响应资料,发现无一例外都具有相同的规律性。在此基础上,笔者提出了对于同震水位振荡,温度下降的气体脱逸模式,并对气体脱逸的两种途径进行了动力学的分析。  相似文献   

4.
井-含水层系统水文地质参数是地下水/含水层水流模型中的关键参数,这些参数通常通过室内实验、野外试验和模型反演获取。基于新10井水位对远场地震的同震响应,通过频谱法分析了该井水震波与地震波的相关性,提出了一种利用水震波信号(主要是瑞利波引起)反演获取承压含水层水文地质参数的方法。结果表明新10井水震波与地震波在变化形态、频谱特征上均具有很好的一致性,估算得到的新10井-含水层系统的储水系数值为1.33×10~(-5)~1.64×10~(-5),渗透系数值为57~87 m/d。提出的承压井-含水层系统水文参数估算法具有很好的实用性,可为地下水管理、地震机理分析等提供一种新的技术方法。  相似文献   

5.
本文探析了汶川地震近区深层井孔-含水层系统在不受水量交换的影响下地下水位的动态变化特征。结果表明,大地震的发生往往能够引起较大范围内深层井孔-含水层系统地下水位明显的异常变化,地震引起的地下水位异常变化特征比较复杂,具有异常形态变化多样,变化幅度不等,变化空间分布不均一,时间分布多阶段以及随时空分布迁移等特点。同时,认为引起汶川地震震时和震后井孔-含水层系统水位异常的机理主要有两个:地震发生时映秀—北川断裂两侧岩体发生错动,引起沿岩体破裂方向(NE)断层附近含水层的地下水位发生显著的突变现象;地震波的传播作用引起云南一带地下水位发生振荡现象。  相似文献   

6.
为求取含水层水文地质参数,常用的试验方法是抽水试验。在进行抽水试验时,经常有越流现象,计算时一般采用越流模型计算。越流模型假定非抽水含水层的水位恒定不变,但在实际抽水过程中,抽水含水层和非抽水含水层间通过越流相互影响、相互作用。如果只考虑抽水含水层的水位变化而不考虑非抽水含水层的水位变化,会导致计算的水文地质参数不准确。实际工作中,有时会在非抽水含水层中布置一口观测井来观测抽水含水层抽水时对非抽水含水层的影响。如果采用多层含水层系统模型的方法,即可利用各含水层观测井中的数据计算出每个含水层和相关弱透水层的水文地质参数,提高参数计算精度、节省资金和工作量。  相似文献   

7.
由地震波引起的地下水位振荡和持久性变化特征被广泛探讨,然而水位对S和Love波的响应及敞口自流井井孔储积效应的校正未得到定量化研究。以理想孔隙弹性介质线性孔隙弹性理论为基础,探究了井-含水层系统孔隙压力变化与体应变和偏应变之间的数学表达式,通过对2011年3月11日日本Mw9. 0地震引起的北京昌平地震台地下水观测井实测水位变化与曲线拟合得到的计算值对比,肯定了孔隙压力的影响因素并求解岩石线弹性系数BKu。与潮汐分析方法对比,验证了由地震方法推算的岩石弹性特性代表实际的含水层特征。此外相关系数结果表明水位振荡同时受到体应力和偏应力的共同影响。  相似文献   

8.
通过采用单位面积河流在单位水头差作用下的渗漏量来表征河流渗漏能力,建立渗流井取水理想模型,分别计算了在不同河流渗漏能力和含水层渗透性能条件下,竖井降深对渗流井出水量的影响。建立渗流井取水非稳定流模型,计算了在前期稳定竖井降深不同条件下,河流断流后渗流井出水量衰减过程及竖井降深发展过程。提出渗流井合理竖井降深应根据河流与地下水是否脱节以及含水层渗透性能,在岸边渗流井中部及一侧各布设一个观测孔,根据观测孔水位进行确定。对于含水层渗透性能较强地区,渗流井竖井降深应使得渗流井范围内地下水位与河流脱节,但高于辐射孔顶面;对于含水层渗透性能较差地区,渗流井竖井降深应使得侧部观测孔水位接近河床底面或刚出现脱节。  相似文献   

9.
万迪堃等在《华北地震科学》第8卷第2期撰文认为,我国地震地下水动态观测井网建点以来所取得的资料表明,同样是承压水,静水位和“动水位”的映震能力有明显不同,“动水他”的映震能力明显优于静水位。“动水位”观测是将自流井的流量观测转变为“水位”观测的方法。“动水位”是指在一定放水量条件下,井管中的水面相对于排水管中心的高度,与水文地质学中动水位的概念是不一致的,不是真正的动水位,它的变化反映排水量的变化。“动水位”观测较静水位观测更“灵敏”的原因初步认为有四个方面:首先“动水位”观测实质上  相似文献   

10.
武汉一级阶地地层具有典型的二元结构特征,从浅层至深层土体渗透性逐渐增加,在基坑工程开挖降水过程中,随着疏干含水层水位的下降,各层土体水位变化特点各不相同,水位的变化影响着土体固结的压缩变形。采用现场群井抽水试验的方法,通过在抽水试验期间对不同深度含水层水位的观测及不同深度土体沉降的监测,结合各层土体性质及相关理论对武汉一级阶地基坑降水引起的土层水位变化及压缩变形规律进行研究。结果表明,武汉一级阶地基坑降水水位变化存在着明显的时空效应,沉降与水位变化密切相关,且沉降过程中土层中出现架空效应。  相似文献   

11.
There are two co-seismic faults which developed when the Wenchuan earthquake happened. One occurred along the active fault zone in the central Longmen Mts.and the other in the front of Longmen Mts.The length of which is more than 270 km and about 80 km respectively.The co-seismic fault shows a reverse flexure belt with strike of N45°-60°E in the ground,which caused uplift at its northwest side and subsidence at the southeast.The fault face dips to the northwest with a dip angle ranging from 50°to 60°.The...  相似文献   

12.
八宝山断裂带是北京西部的一条活动断裂,观测表明其形变、地下水位和降水之间存在强相关性。从大灰厂观测站的断裂带条件和观测系统布置来判断,这种强相关性是浅部破碎岩体渗流-应力耦合机制的结果。断裂带浅部岩体可以分为无压区和承压区。降水能够直接入渗补给无压区,也能够渗入到承压区上部的上盘岩体风化带,从而同时影响断裂带和风化带的地下水位。一个7参数的线性水力耦合模型给出了与实测动态基本一致的垂向形变、地下水位模拟结果。模型分析表明观测到的垂向变形主要由无压区地下水位升降引起的膨胀和收缩变形构成,而上盘湿润或疏干引起的重量变化对垂向变形贡献很小。由于断裂带的地下水排泄基准面和水准基台值可能存在某种外在因素引起的变化,模型参数可能不够稳定,需要进一步调查研究。  相似文献   

13.
About 60 hydrologic changes in response to the Chi-Chi earthquake with Ms7.6 on September 21, 1999, occurred in 52 wells, including groundwater level, temperature, discharge rate, well pressure and radon, etc., in the subsurface fluid monitoring network. These response changes were mainly co-seismic, but some pre- and post-earthquake changes occurred mainly within 5 days before and after the Chi-Chi earthquake. The response changes of different wells clustering in different tectonic areas showed different features. These changes are distributed in five areas named as A, B, C, D and E. The response changes in A area with short hypo-central distance (less than 550 km) were mainly pre-earthquake changes occurring more than 5 days before the event. Those in area B (in Huanan tectonic block) and C (in Huabei tectonic block) were mainly co-seismic changes. The hypo-central distance is about 1100–1280 and 800–1160 km, respectively. These changes were high-frequency water-level oscillations induced by seismic waves and accompanied by prominent and permanent water-level jumps and drops. There are also some post-seismic changes including discharge rate and water radon and well pressure changes in area C. Those in area D in the Yanshan tectonic block were mainly co-seismic and post-seismic changes including water level, water temperature, and water radon concentration, etc., showing prominent and permanent water-level jumps and drops and rising concentrations of water radon. The hypo-central distance is about 1750–2060 km. Those in Area E were mainly co-seismic changes showing prominent and permanent water-level jump. The hypo-central distance is about 1810–2120 km. Three moderate earthquakes occurred in area D and one strong earthquake occurred in area E 4 months after the Chi-Chi earthquake. The different features of the response changes might be caused by the changes of local hydrologic conditions (like permeability) induced by seismic waves. On the other hand, these response changes might indicate the near-critical conditions in the area where the response changes clustered. Such changes might be understood by the crustal buckling hypothesis. It is thought that the response changes might be a kind of precursor that implies elevated earthquake risk in the region.  相似文献   

14.
5.12汶川8.0级地震断层的同震位移方式、大小和空间变化为检验断层几何学、运动学与动力学分析理论与方法提供了一个现实范例。本文通过对汶川8.0级地震断层同震位移的几何学、运动学特征和可能的深部过程分析,并考虑到地震动力作用的影响,探讨了断层同震位移的地质意义和断层运动学模型问题,继而讨论了汶川8.0级地震过程中所呈现出的断层构造变形的现象对断裂构造分析的有关理论和方法的启示。提出了如下初步认识:(1)根据地震破裂面两侧地表高程差确定的断层垂直同震位移,并不完全是深部震源破裂的构造位移扩展到地表所致,而是包含了地震动力作用对断层破裂面两侧深部岩体的结构损伤破坏(膨胀)强烈程度差异所形成的非构造位移;(2)汶川地震的发震断层走滑-逆冲位移大小和方式的空间变化,可以用区域稳态构造应力和地震动力的联合作用给予合理解释,即断层的逆冲位移成分可以归因于为垂直断层的南东向的区域构造挤压应力作用之结果,而水平走滑位移则与震源体破坏过程形成的地震动力作用方向与不同区段断层的交角变化所致,即震源体上方映秀-北川断层南段和彭灌-江油断层,无论是区域构造应力,还是地震动力,都与断层走向近于直交,因此,断层以逆冲为主;而映秀-北川断...  相似文献   

15.
北京北部地区深层热水开发对浅层冷水的影响   总被引:1,自引:1,他引:0  
北京北部有小汤山和沙河2个地热田,呈三角形展布,东部边界为黄庄-高丽营断裂,西部边界为南口-孙河断裂.北部边界为阿苏卫-小汤山断裂。热储层为蓟县系雾迷山组、铁岭组和寒武系-奥陶系碳酸盐岩岩溶裂隙含水层.热储盖层为青白口系页岩、石炭系-二叠系砂页岩和侏罗系火山岩隔水层。该区雨水、浅层基岩冷水和深层基岩热水的H、O同位素组成基本上都落在克雷格降水线上,表明区内冷水与热水均来源于大气降水。热水的^3H值表现出北高南低的特点.说明热水与冷水一样自北向南流动。重点分析了深层热水开采对浅层地震观测井中冷水动态的影响,以及这种影响在不同的水文地质条件、离开采井不同距离和不同测项方面表现出的差异。结果表明,北京北部深层热水开采对浅层冷水动态的影响距离约为5km.对位于导水断裂带附近的观测井的影响最为明显。  相似文献   

16.
剪切带的流体压力因关系着地震断层的滑动强度以及应力释放过程一直备受重视。断层带的渗透率结构对认识断层带内流体活动状况、断层强度、摩擦稳定性以及同震过程等至关重要。文中介绍了断层带渗透率研究的原理、方法,总结了国内外最新的研究成果。脆性域断层的渗透率表现为核部低、两侧高的典型结构,断层泥通常具有最低的渗透率和强各向异性。在地震周期中,断层带的渗透性表现为突然增强-逐渐降低的过程。胶结、水岩反应及溶解-沉淀是间震期断层愈合的主要方式。热压作用是一种有效的断层弱化机制。当断层泥的渗透率小于10-18 m2量级时,地震会伴随强烈的同震热压效应。  相似文献   

17.
Field investigations allow to constrain the co-seismic surface rupture zone of ~400km with a strike-slip up to 16.3 m associated with the 2001Mw 7.8 Central Kunlun earthquake that occurred along the western segment of the Kunlun fault,northern Tibet.The co-seismic rupture structures are almost duplicated on the pre-existing fault traces of the Kunlun fault.The deformational characteristics of the co-seismic surface ruptures reveal that the earthquake had a nearly pure strike-slip mechanism.Theg eologic and topographice vidence clearly shows that spatial distributions of the co-seismic surface ruptures are re-stricted by the pre-existing geological structures of the Kunlun fault.  相似文献   

18.
Field evidence has shown that Lembang Fault (West Java, Indonesia) can act as a groundwater flow barrier. There are outcrops along the footwall comprising consolidated brecciated rock with very low permeability, springs and hot springs occurring along down-thrown hanging-wall rock adjacent to the fault, and a high permeability layer of old and young Tangkuban Parahu eruptive materials (hanging wall) juxtaposed against the low permeability of the older volcanic layer of Bukit Tunggul unit (footwall). Two different environmental tracers were utilized in the study: electrical conductivity measurement and stable isotope analysis. Hydraulic head was measured at some wells along the fault and water electrical conductivity measurements were carried out in a small catchment, the upper part of Cikapundung River basin, which is located just north of Bandung City. Water samples for stable isotope composition analysis were taken from 19 observation wells distributed randomly inside the basin. All analysis data lead to the recognition that Lembang Fault blocks the groundwater flow. No indication was found for water being recharged at higher elevation in the northern part of Bandung Basin, which means the recharged water in Mount Tangkuban Parahu area does not reach Bandung Plain.  相似文献   

19.
Three boreholes were drilled near the Nojima fault, which the 1995 Hyogoken–Nanbu earthquake occurred on. In order to research the properties and the healing process of the fault, water injection experiments were conducted every 3 years. In this report, we researched the permeability of the fault as a measurement of crack density or porosity of the fault zone. Pore water pressure changes in rock due to the water injections at one borehole were observed as discharge changes or groundwater level changes at the other borehole. Using numerical calculations, the permeability of the fault fracture zone was estimated for each experiment. The permeability has been decreasing as time passed, which is thought to show the fault healing process of the Nojima fault after the 1995 Hyogoken–Nanbu earthquake.  相似文献   

20.
A. Lin  T. Ouchi  A. Chen  T. Maruyama   《Tectonophysics》2001,330(3-4):225-244
A nearly 100-km-long surface rupture zone, called Chelungpu surface rupture zone, occurred mostly along the pre-existing Chelungpu fault on the northwestern side of Taiwan, accompanying the 1999 Chi-Chi Ms 7.6 earthquake. The Chelungpu surface rupture zone can be divided into four segments based on the characteristics of co-seismic displacements, geometry of the surface ruptures and geological structures. These segments generally show a right-step en echelon form and strike NE–SW to N–S, and dip to the east with angles ranging from 50 to 85°. The co-seismic flexural-slip folding structures commonly occurred in or near the surface rupture zone from a few meters to a few hundreds of meters in width, which have an orientation in fold axes parallel or oblique to the surface rupture zone. The displacements measured in the southern three segments are approximately 1.0–3.0 m horizontally and 2.0–4.0 m vertically. The largest displacements were measured in the northern segment, 11.1 m horizontally and 7.5 m vertically, respectively. The amount of co-seismic horizontal shortening caused by flexural-slip folding and reverse faulting in the surface rupture zone is generally less than 3 m. It is evident that the co-seismic displacements of the surface rupture zone are a quantitative surface indicator of the faulting process in the earthquake source fault. The relations between the geometry and geomorphology of the surface rupture zone, dips of the co-seismic faulting planes and the striations on the main fault planes generated during the co-seismic displacement, show that the Chelungpu surface rupture zone is a reverse fault zone with a large left-lateral component.  相似文献   

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