反倾层状边坡弯曲折断的应力及挠度判据

以地质分析为基础 ,将反倾层状边坡的任意岩层概化为受复合作用力的板梁模型 ,通过简单的力学解析 ,开展了反倾层状岩石边坡弯曲折断判据的研究。依据岩层折断时和相临岩层的瞬时关系 ,将岩层下部视为瞬时临空状态 ,考虑岩层自重荷载和上部岩层附加荷载 (上部岩层重力荷载、层间摩擦力 )的共同作用 ,基于最大拉应力准则 ,提出了岩层弯曲折断的应力判据 ;依据应力判据 ,得到了岩层弯曲折断的挠度判据 ;利用应力判据及挠度判据 ,可实现反倾层状边坡弯曲折断的现场判定及其控制设计     

UDEC软件对矿山采空区崩塌过程进行应力分布的研究

为了研究矿山采空区坡体的应力(裂隙)分布情况,并对崩塌过程分析进行检验,本文采用离散元数值软件(UDEC)对纳雍县张家湾镇普洒煤矿采煤过程中覆岩裂隙发生、发展及其变化过程进行模拟。结果表明:随着煤层开采的推进,覆岩裂隙向上发展且密度逐渐增多;由于采空区范围过大时,部分被重新压实,裂隙发育至地表形成开切眼;最后在外力作用下整条裂缝垂直贯通,形成危岩体的发展规律,可为类似的矿山地质灾害防治提供基础依据。     

海冰弯曲强度的研究

简要介绍了国内外海冰弯曲强度研究概况;给出了1990年冬作者在辽东湾西部的实验结果;并且讨论了海冰弯曲强度与应力率的关系。     

基于冠层温度的作物缺水研究进展

冠导温度信息可以很好地反映作物的水分状况。自20世纪70年代以来，基于冠层温度的作物缺水指标的研究经历了三个阶段，即单纯研究冠层温度本身变化特征的第一阶段、以冠层能量平衡原理为基础的作物水分胁迫指数的第二阶段和考虑冠层和土壤的复合温度的水分亏缺指数的第三阶段。指标的局长也由使用手持式红外辐射仪信息扩大到使用航空和卫星遥感信息。这一类指标在点和区域尺度上均可应用。加强这一类指标的研究对于我国北方地区农作物的有效灌溉和区域水资源的管理都有重要意义。     

Elastic response of catamaran wetdeck to liquid impact

The impact of an elastic plate onto the compressible fluid without free surface deformation is considered. The ability of the liquid volume to be deformed is geometrically limited which leads to severe impact conditions. The present analysis is focused on the stresses in the plate and the hydrodynamic loads under the impact. The motivation for this research comes from ship hydrodynamics, where the hulls of a catamaran restrict the liquid outflow and the water impacts onto the wetdeck. The influence of the air on the impact process is investigated. The analysis did not reveal any great advantage of utilizing the air-cushion effect or ejection of air into the water near the impact region to prevent high stresses in the elastic plate. It was found that in the problem considered, the stress peaks far from the plate centre and the one-mode approximation does not provide correct information about the stress level.     

公转轴应力场星球说——地球、火星南南西应力场四组三维构造系

介绍了对地球构造格局,运动方式及其动力源问题研究取得的新成果。它不同于流行已久的以地球自转轴旋转和以软流圈带动岩石圈漂移以及随机的地幔柱（流）为构造动力源的观点,而是与黄赤交角相关的沿公转轴方向的统一应力场,认为中国西部ＮＷＷ向压性,ＮＥＥ与ＮＮＷ是与黄赤交角相关的沿公转轴方向的统一应力场。认为中国西部ＮＷＷ向压性,ＮＥＥ与ＮＮＷ向两组共轭扭性及ＮＮＥ向张性带交接,为来自全球ＳＳＷ主压应力场形成的     

Stress Field Estimations for Colima Volcano, Mexico, Based on Seismic Data

 For first time, during 1991, seismic activity was recorded during an eruption at Colima volcano. We analyze these data to obtain a stress pattern using a composite focal mechanism technique. From the analysis of regional seismicity, the Tamazula Fault and the Armeria River appear as active features and the dip of the slab east of the Jalisco Block is approximately 12°. Southwest of Colima volcano a vertical alignment of seismic events was observed. We estimate five different composite focal mechanism solutions from our data set, which indicate a change of the stress field at the volcano after the 1991 eruption. These solutions suggest that the stress field in the volcanic edifice was controlled by stresses related to the emplacement of magma superimposed on the regional stress field. No evidence of active local faults in the volcanic edifice was found. We propose a model for the eruptive process that involves tilting of the volcanic edifice. Received: 15 October 1995 / Accepted: 26 October 1998     

火山岩坡残积土地区暴雨滑坡泥石流的形成机理

暴雨条件诱发的浅层坡残积土质斜坡破坏的机理受控于土体在低有效围压条件下的应力应变特性。1993年11月4～5日,香港大屿山地区特大局部性暴雨导致在120km2范围内产生自然滑坡泥石流800余处,且绝大多数发生于火山岩风化坡残积土地区。本文对火山岩风化坡残积土开展了室内偏压固结不排水剪和偏压固结常剪应力排水剪试验,揭示了该类土的应力应变特性;在此基础上,分析了暴雨滑坡泥石流的形成机理和过程。     

煤矿矿震应力窗口效应

对煤矿矿震活动特征,震源机制解,与天然地震的相关性以及特殊的环境条件等进行了研究,认为煤矿矿震的孕育和发生受控于区域应力场,具有区域应力变化的灵敏窗口效应,可视为探索天然地震前兆和区域应力场变化的应力窗口。     

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。