广西十万大山盆地下二叠统生物礁古油藏及隐伏礁预测

广西宁明县亭亮下二叠统茅口组生物礁古油藏,为十万大山盆地已暴露破坏的礁古油藏之一。该古油藏的含沥青储层主要分布于礁体的上部和顶部,含沥青礁灰岩厚达９８ｍ以上,礁储层次生溶孔的形成与分布主要受控于深埋有机溶剂作用,同时在空间上还与礁顶部古风化壳和不整合面密切相关,论文深入探讨了礁古油藏形成的主要成岩作用类型及其埋藏一构造发展史,有机质演化史及成岩孔隙演化史三者的配置关系和成藏机理,另据地震和电法资料     

中国东北全新世干湿状况的演变

通过综合分析植物花粉,沙土埋藏土壤,泥炭形成与发展,沙丘活动历史,黄土状土堆积和黑土发育等多种资料表明,我国东北地区的湿润程度或土壤水分含量在５ｋａ ＢＰ以前的早中全新世较低,中晚全新世不能增加,早中全新世最干燥时段出现的＾１４Ｃ年代９－８ｋａ ＢＰ,中晚全新世湿润时期可能是最近的２ｋａ,近现代气候比过去１０ｋａ平均状况湿润。     

河南西峡盆地恐龙蛋化石及埋藏特征

产于西峡盆地的恐龙蛋化石计有７ 科、８ 属、１０ 种以上, 主要分布于晚白垩世的高沟组和马家村组。其埋藏特征为： 含蛋层数多, 自下而上约２０ 层; 恐龙蛋大都为原地埋藏,成窝性好, 化石完整; 恐龙蛋集中区分布在冲积扇下、中部及洪泛平原内; 不同类型的恐龙蛋可在同一层面或上、下层中产出; 恐龙蛋在窝中的不同排列形式反映了恐龙产蛋的多样化;原地埋藏的恐龙蛋化石多产于一个正粒序层中、上部的细碎物中     

不滑移状态下深埋圆形隧道地震响应研究

地下结构的地震响应主要取决于由地震波传播产生的土体变形与土结相互作用。剪切波传播过程中将会引起隧道衬砌的椭圆化变形,进而降低衬砌有效承载力。剪切波作用下的深埋圆形隧道可认为处于均质的纯剪状态,基于相对刚度法的拟静力解析解可充分考虑土结相互作用对隧道结构内力的影响。基于此,本文将通过有限元数值分析获得的自由场地地基变形引入不滑移状态下深埋圆形隧道内力求解公式,并结合二维和三维数值模拟途径,将动力分析结果与解析解结果进行对比分析,以评价各种解析方法的适用性和数值途径的可靠性。     

Effect of irregular structural configuration on floor acceleration demand in hill‐side buildings

A suite of reinforced‐concrete frame buildings located on hill sides, with 2 different structural configurations, viz step‐back and split‐foundation, are analyzed to study their floor response. Both step‐back and split‐foundation structural configurations lead to torsional effects in the direction across the slope due to the presence of shorter columns on the uphill side. Peak floor acceleration and floor response spectra are obtained at each storey's center of rigidity and at both its stiff and flexible edges. As reported in previous studies as well, it is observed that the floor response spectra are better correlated with the ground response spectrum. Therefore, the floor spectral amplification functions are obtained as the ratio of spectral ordinates at different floor levels to the one at the ground level. Peaks are observed in the spectral amplification functions corresponding to the first 2 modes in the upper portion of the hill‐side buildings, whereas a single peak corresponding to a specific kth mode of vibration is observed on the floors below the uppermost foundation level. Based on the numerical study for the step‐back and split‐foundation hill‐side buildings, simple floor spectral amplification functions are proposed and validated. The proposed spectral amplification functions take into account both the buildings' plan and elevation irregularities and can be used for seismic design of acceleration‐sensitive nonstructural components, given that the supporting structure's dynamic characteristics, torsional rotation, ground‐motion response spectrum, and location of the nonstructural components within the supporting structure are known, because current code models are actually not applicable to hill‐side buildings.     

Analytic wave series solution of out-of-plane(SH) waves diffraction by an almost semi-circular shallow cylindrical hill

A closed-form wave equation analytic solution of two-dimensional scattering and diffraction of outof-plane(SH) waves by an almost semi-circular shallow cylindrical hill on a flat, elastic and homogeneous half space is proposed by applying the discrete Fourier series expansions of sine and cosine functions. The semi-circular hill problem is discussed as a special case for the new formulated equation.Compared with the previous semi-circular cases solutions, the present method can give surface displacement amplitudes which agrees well with previous results. Although the proposed equation can only solve the problem of SH-waves diffracted by almost semi-circular shallow hills, the stress and displacement residual amplitudes are numerical insignificantly everywhere. Moreover, the influences of the depth-towidth ratio(a parameter defined in this paper to evaluate the shallowness of the topography of hills) on ground motions are presented and summarized. The limitations and errors of truncation from Graf's addition theorem and Fourier series equations in the present paper are also discussed.     

冀中坳陷束鹿凹陷潜山不整合特征与油气运聚模式

本文从冀中坳陷束鹿凹陷潜山顶面不整合接触类型及分布规律、结构特征及输导类型出发,精细刻画了不整合面之下半风化岩石层的垂向岩溶分带特征。在此基础上对典型剖面烃源岩热演化、油气运移进行模拟,建立了研究区潜山油气的运聚模式。结果表明,束鹿凹陷潜山顶面不整合包括4种接触类型、5种结构模式,具有3种输导类型,其中斜坡区和洼槽区西部以侧向型为主,斜坡区局部构造高点与洼中隆为侧向+圈闭型,凸起区以侧向+垂向型为主。不整合面之下半风化岩石孔缝洞体系发育,垂向上可划分为表层岩溶带、垂直渗流带以及三个水平潜流带,具有多期岩溶旋回特征。潜山顶部发育的垂直渗流带是油气沿不整合面运移的主力输导层,而内幕发育的多期水平潜流带是油气向内幕运移的潜在通道。深、浅部烃源岩热演化的差异以及与薄层砾岩是否接触导致了斜坡区与洼中隆潜山油气充注的差异,形成了斜坡区晚期薄层砾岩高效中转、不整合侧向运移、水平潜流带向内幕输导、顺向断层向上输导、反向断层圈闭成藏的油气运聚模式。     

A small-scale field check on the Fisher–Lehmann and Bakker–Le Heux cliff degradation models

The paper considers the development of initially straight, steep rock cliffs, bounded above and below by horizontal surfaces, in which basal debris removal is zero and degradation occurs by the weathering away of fine debris from the cliff face to form a scree at its foot. Of the slope degradation models available, the two earliest and simplest, namely the Fisher–Lehmann and the Bakker–Le Heux models, are regarded as most relevant and are briefly summarized. The main purpose of the paper is to check the predictions of these models, particularly with regard to the shape of the rock surface buried beneath the scree, against field data. Such data are sparse. It is concluded that the best field case currently available, despite its small scale, is that provided by the 1·75 m deep ditch which forms part of the experimental earthwork in the chalk on Overton Down, Wiltshire. The predictions of the two models are checked against field measurements made of the stage of degradation reached on each face of the ditch by July 1968, eight years after its excavation. These stages were influenced to different degrees by the presence of a surface turf layer. For the NE face, where this influence was least, the agreement of the predictions of the Fisher–Lehmann model with the actual rock profile is excellent and that of the Bakker–Le Heux model only marginally less so. For the SW face, as expected, the agreements are somewhat less close. These results may be to some extent fortuitous because of the influence of the turves and because the scree slopes tend to be concave rather than rectilinear, as assumed. Also, the free faces decline with time in a manner intermediate between those assumed in the two models. Larger scale field checks are clearly desirable before firm general conclusions can be drawn. Rates of crest recession for the Overton Down ditch are logarithmic with time after a very rapid initial phase. Extrapolation from the early phase of this logarithmic behaviour leads to a close estimate of the time needed for the slope to develop fully. The associated ultimate crest recession is also closely predicted by equations derived from both models. © 1998 John Wiley & Sons, Ltd.     

水井测温在地热普查中的应用

利用水井测温方法确定恒温层温度,以恒温层的温度值作为湖顶地热异常区的下限值,用内插法勾绘温度等值线图,高于该下限值范围的即为地热异常区。曹县庄寨地区的地热普查证明该方法是快速有效的。