全文获取类型
收费全文 | 46篇 |
免费 | 10篇 |
国内免费 | 24篇 |
专业分类
地球物理 | 26篇 |
地质学 | 47篇 |
海洋学 | 6篇 |
综合类 | 1篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 4篇 |
2007年 | 3篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1996年 | 2篇 |
1992年 | 1篇 |
1987年 | 3篇 |
1985年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有80条查询结果,搜索用时 15 毫秒
1.
2.
3.
超高强混凝土短柱抗震性能的试验研究 总被引:4,自引:0,他引:4
通过对12根剪跨比λ=2.0的超高强混凝土短柱在低周反复荷载下抗震性能的试验研究,分析了其破坏形态,并研究了轴压比和配箍率对试件滞回特性和抗震延性的影响,提出了满足一定延性要求(μ△≥3.0)超高强混凝土短柱的轴压比限值和箍筋加密区的最小配箍特征值的建议值。该值可为现行规范的修订提供参考。 相似文献
4.
Ping Wu Yang Guo Dayong Zhu Weiliang Jin Zhenhua Zhang Rongzhu Liang 《Marine Georesources & Geotechnology》2020,38(5):518-526
AbstractThis study developed prestressed high-strength concrete (PHC) piles reinforced with high-strength materials (glass fiber-reinforced polymer (GFRP) bars) for flexural performance enhancement. Flexural strengths and behaviors of PHC piles reinforced with hybrid GFRP and steel bars were experimentally investigated, respectively. Large-scale specimens with total lengths of 12,000?mm and diameters of 600?mm were constructed and tested under bending, accompanied by evaluation of effects of non-prestressed reinforcement type and longitudinal reinforcement ratio. J-factors were calculated to evaluate deformability of all the specimens. PHC piles reinforced with GFRP bars were demonstrated to have much higher flexural capacity than those reinforced with steel bars. Moreover, strains at the midspans of cross sections of all the specimens basically conformed to the assumption of plane section. Failure of PHC piles reinforced with GFRP bars was attributable to gradual concrete crushing, while that of PHC piles reinforced with steel bars resulted from steel yielding. Results of this study were expected to provide theoretical basis for wide engineering applications of PHC piles reinforced with hybrid GFRP bars and steel bars in marine structures. 相似文献
5.
B. Stimpson 《Geotechnical and Geological Engineering》1987,5(3):299-305
Summary The shear stiffness of a grouted, rock bolt intersecting a discontinuity controls the amount of shear movement that can occur for a given shear force. In this paper an analytical model is developed for estimating the shear stiffness of a single bolt as a function of bolt inclination, hole and bolt diameter, bolt, grout and rock Young's moduli, and aperture (opening) across the discontinuity, and sensitivity studies conducted to determine the most significant of these variables as predicted by the model. 相似文献
6.
7.
8.
U.?M.?Rao?KaranamEmail author S.?K.?Dasyapu 《Geotechnical and Geological Engineering》2005,23(3):297-308
Rock bolts are widely used for rock reinforcement in hard-rock mining and civil engineering since a long time. However the use of fully grouted rock bolts and cable bolts is limited in coal mines. In order to improve performance of the rock bolts as a supplementary roof support system for any type of roof condition in coal measured formations, it is necessary to have a good understanding of the behavior of the bolt–grout and grout–rock interactions as well as the mechanism of load transfer in rock bolts.As the performance of grouted bolts depends on bond strength, extensive laboratory pullout as well as pushout tests were conducted in the present investigations with the variations in the bolt diameters, length and cement–water mixing ratios of grout. The load–displacement curves were developed and were verified with the numerical results obtained from finite element analysis using ALGOR software.Numerical models were validated for pushout tests and a detailed analysis was carried out to know the displacement, stress, strain distribution along the bolt. 相似文献
9.
An analytical model on the general behaviour of a tunnel head, reinforced by finite length bolts is proposed. This model is based on the homogenization method and spherical symmetry assumption. Despite its simplicity, and in consequence its limits of validity, it does allow a quick estimation of the key design parameters: frontal displacement, extension of decompressed zone, ground stresses and bolt tension, and constitutes thereby a very useful and handy tool for design engineers. In particular, the influence of the reinforcement length, as well as other important design parameters, are studied by the proposed model. The charts resulting from the parametric studies are directly applicable. Otherwise, the comparison to a 3D numerical model is also presented in this paper. The first results provide the validation of the analytical solution, at least in terms of average extrusion movements. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
10.
It is widely accepted that ductility design improves the seismic capacity of structures worldwide. Nevertheless, inelastic deformation allows serious damage to occur in structures. Previous studies have shown that a certain level of postyield stiffness may reduce both the peak displacement and residual deformation of a structure. In recent years, several high-strength elastic materials, such as fiber-reinforced polymer (FRP) and high-strength steel bars, have been developed. Application of these materials can easily provide a structure with a much higher and more stable postyield stiffness. Many materials, members, and structures that incorporate both high-strength elastic materials and conventional materials show significant postyield hardening (PYH) behaviors. The significant postyield stiffness of PYH structures can help effectively reduce both peak and residual deformations, providing a choice when designing resilient structures. However, the findings of previous studies of structures with elastic-perfectly plastic (EPP) behavior or small postyield stiffness may not be accurate for PYH structures. The postyield stiffness of a structure must be considered an important primary structural parameter, in addition to initial stiffness, yielding strength, and ductility. In this paper, extensive time history and statistical analyses are carried out for PYH single–degree-of-freedom (SDOF) systems. The mean values and coefficients of variation of the peak displacement and residual deformation are obtained and discussed. A new R-μp-T-α relationship and damage index for PYH structures are proposed. A theoretical model for the calculation of residual deformation is also established. These models provide a basis for developing the appropriate seismic design and performance evaluation procedures for PYH structures. 相似文献