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111.
四川盆地川西坳陷高异常地层压力分布特征 总被引:6,自引:0,他引:6
本文通过分析川西坳陷20多个含气构造的主要地层压力资料,对川坳陷高异常地层压力的分布特征有了一定的认识。认为川西高异常地层压力在纵向层位上主要分布于侏罗系和上三叠统,压力分段明显,相同的力段在不同的构造既不等时也不等深;在平面上高异常地层压力分布广泛,超高压区刚分布于川西北地区,并形成两个超高压中心,整个高异常地层压力的分布虽然总体上基本一致,但在不同层位,不同时期也存在着差异。 相似文献
112.
Design and Long-Term Monitoring of Tokyo International Airport Extension Project Constructed on Super-Soft Ground 总被引:1,自引:0,他引:1
K. Morohoshi K. Yoshinaga M. Miyata I. Sasaki H. Saitoh M. Tokoro N. Fukuda T. Fujii K. Yamada M. Ishikawa 《Geotechnical and Geological Engineering》2010,28(3):223-232
To meet the increasing demand for air transportation, Ministry of Land, Infrastructure and Transport had carried out the offshore
extension project at Tokyo International Airport (Haneda Airport). The airport should be constructed to be perfectly level,
but the ground conditions with very thick layers of super soft dredged soils and need for reclamation made the task very difficult.
Because of large amount of consolidation settlement, ground improvement by combined vertical drain method was applied to decrease
residual and differential settlement after opening of new airport. This paper is aimed to introduce the design concept and
method of ground improvement for this project. In addition the result of ground improvement is keeping satisfactory performance
for operating airport confirmed by long-term monitoring for airport facilities. 相似文献
113.
同普杂岩体位于藏东江达地区。本文对该杂岩体岩相学、年代学、主微量元素以及Sr-Nd同位素进行了详细的研究。结果表明,该杂岩体主要由石英闪长岩、花岗闪长岩、含黑云母花岗岩和斑状花岗岩4种岩石类型组成,前三者形成时代分别为262.8±1.5Ma、263.9±1.9Ma、263.7±1.6Ma。其中,含黑云母花岗岩与斑状花岗岩呈渐变过渡关系,它们和花岗闪长岩一起均具有高SiO2(65.1%~76.6%)、高K2O+Na2O(4.84%~8.13%),低MgO(0.25%~2.28%),低FeOT(0.99%~4.44%),高A/CNK值(除一件样品外两者A/CNK值均大于1.1),以及Ba、Sr、Eu亏损等,均符合强过铝质S型花岗岩的特征。但前两者与后者CaO/Na2O、Rb/Ba、Rb/Sr值均存在明显差异,哈克图解上也不存在线性关系,表明它们源区存在差异。石英闪长岩则具有相对低的SiO2(54.2%~55.4%)、低K2O+Na2O(3.15%~4.72%),高MgO(3.78%~4.79%),高FeOT(6.13%~8.09%)等特征。其还具有明显的Nb负异常,不具有Sr的负异常,以及轻稀土相对富集等,均符合岛弧岩浆岩的特征。Sr-Nd同位素特征显示,斑状花岗岩与花岗闪长岩具有相似的初始Sr比值(分别为0.7099,0.7125)和εNd(t)值(分别为-8.6,-10.3),而石英闪长岩则具有较低的初始Sr比值(0.7062),较高的εNd(t)值(1.37)。前两者均落入研究区S型花岗岩与高硅流纹岩区域,后者落在金沙江MORB的下方。通过综合分析,本文认为同普杂岩体形成于火山弧环境,且各岩石类型具有不同的源区:含黑云母花岗岩、斑状花岗岩与花岗闪长岩的源区分别为古老的泥质变质岩和贫泥质的变质砂岩;石英闪长岩则来自富集地幔。表明在晚二叠世早期(~263Ma)金沙江洋盆仍处于俯冲阶段,江达地区主要受金沙江洋盆俯冲消减体系控制而非地幔柱体系。 相似文献
114.
胶州--莱阳盆地白垩纪莱阳群中的震积岩及构造意义讨论 总被引:14,自引:2,他引:14
通过对胶州-莱阳盆地沉积层的野外考察和岩心观察,系统分析了莱阳群的沉积特征及其变化规律,鉴别出一些较典型的震积岩类型;较详细描述了其中的粉砂质液化脉、震裂液化角砾岩、震褶岩和砂枕构造等地震液化特征。最后从盆地的区域地质背景出发,初步认为白垩纪早期胶州-莱阳盆地的形成与其南部苏鲁造山带的后期隆升同时,造成研究区总体处于伸展-裂解的构造环境之中。强烈的同沉积构造活动伴随频繁的地震发生,致使盆地内早期沉积的莱阳群以普遍发育震积岩为特征。 相似文献
115.
瑶琳仙境洞穴动物的研究 总被引:6,自引:2,他引:6
1980年11月至1986年5月,在瑶琳洞内各种生境作了观察、采集,并对微形动物进行了实验室培养。已经鉴定的洞穴动物有35种,隶属于28科、32属。从蜘蛛种类同五个不同面积溶洞的关系看,相关系数(r)为0.9707,两者为正相关。并分析了洞穴动物的营养源和食物链,在此基础上,还阐述了洞穴动物的保护利用问题。 相似文献
116.
载炭泡塑吸附法对金有良好的吸附性能,但只能用于抽滤吸附不能振荡吸附,分析手续繁杂。本文以载炭泡塑振荡吸附-电感耦合等离子体发射光谱法测定金矿石的金量。样品在650℃高温灼烧2 h,用50%王水和10%氯化铁加热溶解,溶液冷却后加入5%高锰酸钾氧化,用中密度规格的载炭泡塑两次振荡吸附溶液中的金,然后于580℃高温灼烧后以50%王水溶解灰分,直接用ICP-OES测定金量。方法检出限(3σ)为0.002μg/g,精密度(RSD,n=11)小于3.7%。本方法对金的吸附率大于99.9%,测定范围为0.01~90μg/g,对不同类型金矿石的适应性强,解决了以往泡塑吸附法吸附率较低、标准系列与样品需同时预处理的问题,对低含量和高含量样品均有较高的准确度。 相似文献
117.
Movement of seasonal eddies in the Bay of Bengal (BOB) and its relation with cyclonic heat potential (CHP) and cyclogenesis
points have been investigated in this study using 6 years (2002–2007) of global ocean monthly analysis datasets based on the
Simple Ocean Data Assimilation (SODA) package (SODA v2.0.4) of Carton et al. (2005) and Indian Meteorological Department cyclogenesis points. The region dominated by anticyclonic eddies with CHP greater than
70 × 107 J/m2 as well as good correlations (>0.9) with sea surface height (SSH) and 26°C isothermal depth (D
26) can be a potential region of cyclogenesis. The region dominated by cyclonic eddies with CHP greater than 50 × 107 J/m2 and good correlation (>0.9) with both SSH and D
26 can serve as a potential region of high-level depression. Potential cyclogenesis regions are the southern BOB (5°N–12°N)
for the post-monsoon season and the head of BOB (north of 15°N) during southwest monsoon. Seven potential regions are identified
for the eddy formation for different seasons, which are consistent with the cyclogenesis points. The CHP distributions alone
are able to explain the cyclone tracks for the pre-monsoon and post-monsoon seasons but not for the monsoon season. 相似文献
118.
Frozen ground is significantly stiffer than unfrozen ground. For bridges supported on deep foundations, bridge stiffness is also
measurably higher in winter months. Significant changes due to seasonal freezing in bridge pier boundary conditions require additional
detailing in order to ensure a ductile performance of the bridge during a design earthquake event. This paper reports the latest
results obtained from a project that systematically investigated the effects of seasonally frozen soil on the seismic behavior of
highway bridges in cold regions. A bridge was chosen and was monitored to study its seismic performance and assess the impact
of seasonally frozen soil on its dynamic properties. A Finite Element (FE) model was created for this bridge to analyze the impact
of seasonal frost. It was found that when frost depth reaches 1.2 m, the first transverse modal frequency increases about 200%
when compared with the no-frost case. The results show that seasonal frost has a significant impact on the overall dynamic behavior
of bridges supported by pile foundations in cold regions, and that these effects should be accounted for in seismic design. 相似文献
119.
海底管道出露悬空环境风险的定量评价研究 总被引:1,自引:0,他引:1
海底管道是海洋油气输送的主要方式,其运行状况直接关系到海上油气田的安全和海洋生态环境的质量。本文先以海底管道出露悬空作为故障树的顶事件,分析出海洋环境中各项基本事件,构建针对海洋环境的海底管道故障树模型;再以灰色模糊识别为理论基础,量化对海底管道安全有影响的海洋环境因素,并以层次分析法对每个风险因素进行分级赋权,确定评价指标范围和权重,进而构建海洋环境条件的海底管道风险评价体系。利用该体系对平湖油气田海底管道4个区段进行环境风险评价,避免了将整段管道一同评价导致的信息均等化,评价结果不能真实反映风险等级高的区段的情况;评价结果与管道2014~2016年现场检测数据对比,两者均显示P2分区中海底管道的风险等级较高,说明了该模型具有一定的合理性和实用性。 相似文献
120.
Fractal modelling has been applied extensively as a means of characterizing the spatial distribution of geological phenomena
that display self-similarity at differing scales of measurement. A fractal distribution exists where the number of objects
exhibiting values larger than a specified magnitude displays a power-law dependence on that magnitude, and where this relationship
is scale-invariant. This paper shows that a number of distributions, including power-function, Pareto, log-normal and Zipf,
display fractal properties under certain conditions and that this may be used as the mathematical basis for developing fractal
models for data exhibiting such distributions. Population limits, derived from fractal modelling using a summation method,
are compared with those derived from more conventional probability plot modelling of stream sediment geochemical data from
north-eastern New South Wales. Despite some degree of subjectivity in determining the number of populations to use in the
models, both the fractal and probability plot modelling have assisted in isolating anomalous observations in the geochemical
data related to the occurrence of mineralisation or lithological differences between sub-catchments. Thresholds for the main
background populations determined by the fractal model are similar to those established using probability plot modelling,
however the summation method displays less capacity to separate out anomalous populations, especially where such populations
display extensive overlap. This suggests, in the geochemical data example provided, that subtle differences in the population
parameters may not significantly alter the fractal dimension. 相似文献