松辽盆地三肇地区油田储层裂缝及地应力特征

在大量裂缝发育特征的观察和统计工作基础上,结合油田开发动态和古构造发育史分析等,应用岩芯古地磁定向,差应变和波速各和异性等研究方法,结果认为三肇地区扶杨油层发育的裂缝走向以近东西向为主,多具高倾角,并可构成规模较大的主裂缝,其在油田注水开发中起着不可轻视的作用。分析表明,裂缝发育的密度与砂层的厚度成反比,与构造曲率成正比。区域最大水平主应力为北西西向,近东西向裂缝为油田最有效裂缝组系。     

北部湾6.1,6.2级地震序列的环境应力场

应用Ｐ波初动半周期直接测定环境剪应力值的方法,测定了北部湾６．１,６．２级地震前后中小地震的环境剪应力值τ０,由此分析了北部湾地震过程的环境应力场特征。结果表明,北部湾６．１级地震后平均剪应力值较高,达１８ＭＰａ左右;６．２级地震及两次５级余震后剪应力值下降很快,降至目前的６ＭＰａ左右。在此基础上对北部湾地震活动趋势作了初步分析。     

不同盐度对多刺裸腹溞内禀增长率的影响

于２５℃时,观察了多刺探腹溞ＭｏｉｎａｍａｃｒｏｃｏｐａＳｔｒａｕｓ在盐度为２‰、３‰、４‰、 ６‰、８‰、１０‰６个浓度梯度下的生殖与生存．试验表明,多刺裸腹溞的寿命随盐度升高而缩短,在 盐度２‰－４‰范围内,每溞的平均产仔量、产仔总量及种群的内禀增长率（ｒ_ｍ）无显著差异,其最 适盐度为２‰－４‰,６‰,为其生殖的盐度上限,经过短期的海水驯化,多刺裸腹溞的生殖和生存盐 度上限可达８‰．     

浅论不同应力状态下坝基层间剪切带弹性力学性质

本文以万家寨水利枢纽坝基Ｓｃｊ０８层间剪切带声波测试资料为依据,论述了不同应力状态下、剪切带弹性力学性质变化过程和机理,其成果对坝基施工过程控制和基础稳定性分析具有一定指导意义。     

1998年11月19日云南宁蒗6.2级地震前地震活动性特征

１９９８ 年１１ 月１９ 日在云南省宁蒗发生了一次 Ｍ６２ 级强烈地震。该次地震前, 震中及邻区地震活动明显增强, 累计频度和应变能释放随时间从线性缓慢增加变为非线性快速增加, 出现孕震空区、多项地震活动参数异常。此外, 地震活动性诸多参数在地震活动处于线性缓慢变化的时间段内, 在空间分布上表现为随机的现象; 在地震活动处于非线性快速变化的时间段内, 这些参数的空间分布表现出向未来震中收缩、集中的明显特征。     

Dynamic variation of ambient shear stress field before and after three strong earthquakes in Yunnan

IntroductionThecrustaltectonicmovementisacomplicatedevolutionprocesswithtimeandspace.Spatially,themovementofcrustaltectoniciscloselyrelatedtotheinter-movementandinteractionofmulti-leveledcrustalblocksinacertainregionandtheirborderfaults.Temporally,themovementiscloselyrelatedtothatofmulti-leveledcrustalblocksandtimesequencedevelopmentofinteraction.Anearthquakeoccurrenceistheresultofsuddenruptureofcrustmediaundertheactionoftectonicstressfield,isalsoacomplicatedprocessinnercrust.Duetotheobviousi…     

Three dimensional tectonic stress field in North China

IntroductionThecrusttectonicstressfieldisoneofthekeyproblemsofgeodynamics,itsmaincontentsareaprobingintospatialdistributionanddynamicevaluationofcrusttectonicstressfield,thentracingtheevolutionprocessofcrusttectonicmovement,learningcontemporarycrusttectoniceventanditsmechanism,thuspredictingthefuturedevelopmentlawoftectonicmovement.Intheendof1970s,aseriesofpaperswerepublishedattheinternationalconferenceonMagnitudeofDeviatoricStressesintheEarth'SCrustandUppermostMantle.Theygavethebriefoutlin…     

Numerical calculations of tectonic stress field of Chinese mainland and its neighboring regions and their applications to explanation of seismic activity

IntroductionChinesemainlandliesinthesoutheastofEurasianPlateandisclampedbyindian,PacificandPhilippineSeaPlates.Besides,itislocatedatbetweenthetwobigseismicactivebeltsintheworldatthesametime.Differingfromtheshowoftwobigseismicbeltswhichhaveseismiczonaldistributionalongplateboundary,Chinesemainlandanditsperipheralareahaveapeculiarcharacter,expressingseismicallylargestrength,highfrequency,widedistribution,shallowfocus,seriousdamage,multiplestyles,extremelynonuniformspace-timedistributionandsoo…     

Modern tectonic stress field in the Chinese mainland inverted from focal mechanism solutions

IntroductionTheinversionapproachofregionalstressfielddevelopedinrecent10to20yearsprovidesausefultoolforstudyingthemeanstressinagivenregion(Angeller,1979;Ellsworth,1981,Xu,Ge,1984).Becauseitusesmultitudinousfaultsinsteadofsinglefault,itcanremovetheinhomogeneityoflocalmediumsoastorevealtheregionalstressinformation.Besides,thismethodproducesaRvalue,whichisdefinedby(O-2--q)/(q--q),andmaydescribestherelativemagnitUdeofintermediateprincipalstress,whereq,acand%arethemaximum,theintermediateandthemi…     

Preliminary research to determine stress districts form focal mechanism solutions in Southwest China and its adjacent area

IntroductionManystudies(Kan,etal,1977;Cheng,1981;Xu,etal,1987;Xie,etal,1993,Mulled,etal,1997)indicatedthatthedirectionsofcrustaltectonicstresseshaveregionalvariation.SimpleanalysesbymeansOfthreeprincipalaxesoffocalmechanismsolutions,whichexpressedasP...