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221.
针对“5·12”地震后,位于北川地区断层破碎带的千枚岩作为路基填料特有的材料,对破碎的千枚岩进行化学成分、物理性质、崩解性等试验。初步认为可以作为路基的底层填料,点荷载强度与多因素有关;破碎千枚岩中的粘土矿物含量与崩解程度有很大关系,压实工程特性与颗粒粗细的相对含量密切相关。根据施工现场试验监测结果表明,通过研究确定的压实工艺可将千枚岩压实到要求的密度,其物理、力学性质得到改善,满足路基要求。 相似文献
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工程实例的试验成果表明:素填土在自然状态下将产生固结,但这种固结除了受自身重力作用外,还受到雨水下渗、阳光照晒和风力风干等因素的影响,且上部主要受雨水下渗、阳光照晒和风力风干的影响,下部则主要受自身重力的作用。因此素填土的这种固结不是单纯的自重固结,我们称之为自然固结。试验结果还表明:经过一定时间后,在雨水下渗和阳光照晒和风力风干的作用下,上部一定深度内的素填土固结度较好,且形成“硬壳层”,填筑时间四年的素填土在6m深度内,其力学性能相当或接近于夯击能为2160kN·m的夯填土,因此可以作为对沉降敏感性要求不高的轻型低型建筑物和道路、小荷载的持力层,这既可节省工程造价,且也是安全的。 相似文献
224.
Depositional architecture and evolution of progradationally stacked lobe complexes in the Eocene Central Basin of Spitsbergen 总被引:1,自引:0,他引:1
Sten‐Andreas Grundvåg Erik P. Johannessen William Helland‐Hansen Piret Plink‐Björklund 《Sedimentology》2014,61(2):535-569
The down‐dip portion of submarine fans comprises terminal lobes that consist of various gravity flow deposits, including turbidites and debrites. Within lobe complexes, lobe deposition commonly takes place in topographic lows created between previous lobes, resulting in an architecture characterized by compensational stacking. However, in some deep water turbidite systems, compensational stacking is less prominent and progradation dominates over aggradation and lateral stacking. Combined outcrop and subsurface data from the Eocene Central Basin of Spitsbergen provide a rare example of submarine fans that comprise progradationally stacked lobes and lobe complexes. Evidence for progradation includes basinward offset stacking of successive lobe complexes, a vertical change from distal to proximal lobe environments as recorded by an upward increase in bed amalgamation, and coarsening and thickening upward trends within the lobes. Slope clinoforms occur immediately above the lobe complexes, suggesting that a shelf‐slope system prograded across the basin in concert with deposition of the lobe complexes. Erosive channels are present in proximal axial lobe settings, whereas shallow channels, scours and terminal lobes dominate further basinward. Terminal lobes are classified as amalgamated, non‐amalgamated or thin‐bedded, consistent with turbidite deposition in lobe axis, off‐axis and fringe settings, respectively. Co‐genetic turbidite–debrite beds, interpreted as being deposited from hybrid sediment gravity flows which consisted of both turbulent and laminar flow phases, occur frequently in lobe off‐axis to fringe settings, and are rare and poorly developed in channels and axial lobe environments. This indicates bypass of the laminar flow phase in proximal settings, and deposition in relative distal unconfined settings. Palaeocurrent data indicate sediment dispersal mainly towards the east, and is consistent with slope and lobe complex progradation perpendicular to the NNW–SSE trending basin margin. 相似文献
225.
Ridges that resemble terrestrial moraines are commonly visible at the foot of many mid-latitude crater walls in Mars Global Surveyor Mars Orbiter Camera images. These moraine-like ridges are often associated with hillside gullies, mantling material, and glacier-like flows, and are usually in contact with crater fill, suggesting possible interrelationships. We consider terrestrial glacier systems that may be analogs of martian moraine-like ridges and glacier-like flows and suggest that the formation of some gullies and crater fill is intimately tied to ice deposition, ice flow, and rock-glacier processes. Upper limits on age suggest the possibility that many of these features formed during the last, or last few, high obliquity cycles. 相似文献
226.
文章通过对桂林市某综合楼地基处理的成功经验 ,对采用单管高压旋喷工艺进行杂填土处理的设计与施工作了介绍。 相似文献
227.
Geo-neutrinos emitted by heat-producing elements (U, Th and K) represent a unique probe of the Earth interior. The characterization
of their fluxes is subject, however, to rather large and highly correlated uncertainties. The geochemical covariance of the
U, Th and K abundances in various Earth reservoirs induces positive correlations among the associated geo-neutrino fluxes,
and between these and the radiogenic heat. Mass-balance constraints in the Bulk Silicate Earth (BSE) tend instead to anti-correlate
the radiogenic element abundances in complementary reservoirs. Experimental geo-neutrino observables may be further (anti)correlated
by instrumental effects. In this context, we propose a systematic approach to covariance matrices, based on the fact that
all the relevant geo-neutrino observables and constraints can be expressed as linear functions of the U, Th and K abundances
in the Earth’s reservoirs (with relatively well-known coefficients). We briefly discuss here the construction of a tentative
“geo-neutrino source model” (GNSM) for the U, Th, and K abundances in the main Earth reservoirs, based on selected geophysical
and geochemical data and models (when available), on plausible hypotheses (when possible), and admittedly on arbitrary assumptions
(when unavoidable). We use then the GNSM to make predictions about several experiments (“forward approach”), and to show how
future data can constrain a posteriori the error matrix of the model itself (“backward approach”). The method may provide a useful statistical framework for evaluating
the impact and the global consistency of prospective geo-neutrino measurements and Earth models. 相似文献
228.
在气象信息综合分析处理系统的本地化过程中,可视化简单编程指令代码、格点数据分析显示系统和公式翻译器之间混合开发技术的研究是非常重要的问题。研究了利用可视化简单编程指令代码开发操作界面、公式翻译器运算数据、格点数据分析显示系统绘图三者有效结合的编程技巧,并通过两个具体案例给予了详细的技术说明。 相似文献
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230.
求取岩石基质体积模量的线形拟合方法(英文) 总被引:2,自引:2,他引:0
岩石基质的体积模量或其倒数--压缩系数,在进行油气预测的流体替换和孔隙度反演时,是重要的输入参数,但是利用现有方法很难准确求得。文中提出了一种求取该参数的线形拟合方法,该方法通过对Gassmann方程的合理简化并引入Eshelby-Walsh干燥岩石椭球包体近似公式,获得了计算岩石基质压缩系数的拟合公式,可方便地利用公式计算该参数。实际碳酸盐岩岩样的岩石物理测试分析显示:利用饱和岩样和干燥岩样测得的基质压缩系数的差异小于1%,说明所求参数是正确的,可靠的。 相似文献