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1.
Robert M. Rosenswig Ricardo López-Torrijos Caroline E. Antonelli Rebecca R. Mendelsohn 《Journal of archaeological science》2013
Recent lidar and pedestrian surface surveys have remapped the well-known Mesoamerican site of Izapa and the surrounding Soconusco piedmont. These data document: 1) occupation from the surrounding piedmont environment, 2) significantly larger estimates of the site's size during both the Formative and Classic periods as well as 3) new architectural features from the monumental site core. Methodological issues are outlined for combining high precision lidar mapping with ground truthing and pedestrian survey that focuses on surface collection of temporally diagnostic artifacts. Results are presented for 670 mounds documented in an area of 43.1 sq km in and around the ancient capital of Izapa. 相似文献
2.
We present a scheme to modify empirical Green's functions by attenuation considering: (1) geometrical spreading; (2) decay in high frequency; (3) regional attenuation; and (4) phase of the signal. The accelerograms computed with the proposed simulation method are compared, in time and frequency domains, with strong ground motions from subduction and intermediate-depth earthquakes recorded in Mexico. It is shown that this simple empirical Green's functions technique can synthesize both the shape and amplitude of the response spectra in the site, considering a postulated seismic source located at different distances from the original one. 相似文献
3.
Seismic assessment of gravity dams is generally carried out using time history analyses. Scaling of the motions is commonly used; however, in contrast to buildings, the performance of scaling procedures at predicting the mean and reducing the dispersion in engineering demand parameters (EDPs) is not known. The main goal of this study is to assess the performance of different scaling procedures in predicting seismic demands on dams. The performance regarding the prediction of the damage and the required number of motions for effective analysis was investigated. The results show that techniques commonly used for moment frames should not readily be applied to these structures. 相似文献
4.
ALANA PENGILLEY CHRISTABEL BRAND JAMES FLEXNER JIM SPECHT ROBIN TORRENCE 《Archaeology in Oceania》2019,54(3):200-213
Compared to elsewhere in Oceania, the history and character of stone axe‐adze production and exchange in the Bismarck Archipelago is very poorly known. To explore the feasibility of using geochemical analysis to trace past social interaction, we conducted a non‐destructive portable XRF study of 97 ground stone artefacts from archaeological contexts in New Britain and the ethnographic collection at the Australian Museum. The study capitalised on the well‐documented spatial distribution of geochemical variation resulting from the plate‐tectonic history of the region. The results indicate that prehistoric communities in New Britain specialised in goods such as ground stone tools or obsidian in order to facilitate social interaction over a large region. 相似文献
5.
This paper presents the results from extensive parametric dynamic analyses of soil-structure systems that focus on the clear modification (increase or decrease) of the acceleration amplitude at the foundation with respect to the free-field, especially for squatty structures. Properties of the systems are selected such as to cover a wide range of meaningful geometries and materials for engineering practice. The results are presented in terms of weighted modification factors of the maximum foundation acceleration amplitude with reference to the corresponding maximum acceleration amplitude at free-field, for squatty and more slender structures. For the large majority of the studied systems, foundation acceleration decreases from the free-field by 10–15% on average. Nevertheless, acceleration demand at the foundation increases compared to the free-field, for 30% of squatty and for 15% of the more slender structures. Modification of the foundation acceleration amplitude is also correlated with the ratio of the predominant period of the input motion to the flexible-base system period. Finally, the findings of this study are compared with sparse available recorded data from the Seismic Hazard Harmonization in Europe database. 相似文献
6.
从《方言疏证》看戴震的校勘特点 总被引：2，自引：0，他引：2
徐玲英 《古籍整理研究学刊》2007,(5):55-60
作为一代考据学大师,戴震将其考据方法运用于校勘,他校勘《方言》较少依据版本,而是博综群籍传注,本之小学六书,以理论断;以求是为根本旨归,大胆改正讹文;发凡起例,首次从致讹角度总结误例。戴震的校勘体现出鲜明的时代学术风尚。 相似文献
7.
Benedikt Halldórsson Símon Ólafsson Ragnar Sigbjörnsson 《Journal of Earthquake Engineering》2013,17(3):343-370
The two Mw 6.5 earthquakes on June 17 and 21, 2000, respectively, in the populated South Iceland Seismic Zone (SISZ) significantly augmented the Icelandic database of strong ground motions, and several strong velocity pulses were recorded at near-fault sites. The strong motions are interpreted via the Specific Barrier Model (SBM) and a mathematical model of near-fault velocity pulses. The data indicates self-similar source scaling and significantly greater attenuation of seismic waves than in other interplate regions. Through inversion of the data a new attenuation function for the SISZ has been adopted, which results in unbiased simulations. For the first time, the characteristics of the recorded near-fault pulses have been identified and compared to the worldwide database of such records. The SBM and the near-fault pulse model combine naturally in a fast and efficient synthesis of realistic, broad-band strong ground motions in the far-fault and near-fault region. Such simulations are showcased for the June 2000 earthquakes and indicate that the modeling approach adopted in this study is an effective tool for the estimation of realistic earthquake ground motions in the SISZ. 相似文献
8.
Acceleration response of simple yielding structure is proportional to its own weight, but it is limited by yield strength. Thus, using rocking columns that reduces global yield strength, a limited acceleration is achieved. However, the displacement becomes large due to lower strength and higher inelasticity, but it can be controlled by adding damping. Performing fragility analyses, the seismic response of R/C frame structures with rocking columns and viscous dampers is investigated. Near field MCEER ground motions are considered. The analyses show that the story accelerations are reduced by using rocking columns, while the story displacements are controlled by using viscous dampers. 相似文献
9.
P. Suhadolc L. Moratto G. Costa P. Triantafyllidis 《Journal of Earthquake Engineering》2013,17(4):560-581
In Turkey, with the occurrence of almost every strong and even moderate earthquake, damage to masonry minarets is observed. In the present work, efficiency of vertical post-tensioning application to reinforce masonry minarets against earthquakes has been investigated. Considering a representative minaret and its post-tensioned counterpart, and performing spectral and time-history analyses, the effects of post-tensioning on the axial stresses, top lateral displacements and overturning safety have been determined. Obtained results have shown that vertical post-tensioning application is a very efficient method to reduce axial tensile stresses and lateral displacements, and to assure the overturning safety of masonry minarets against earthquakes. 相似文献
10.
M. Moghaddasi M. Cubrinovski J. G. Chase S. Pampanin A. Carr 《Journal of Earthquake Engineering》2013,17(6):820-850
This article highlights soil-structure interaction (SSI) effects on the seismic structural response accounting for uncertainties in the model parameters and input ground motions. A probabilistic Monte Carlo methodology was used to conduct approximately six million dynamic time-history simulations using an established rheological soil-shallow foundation-structure model. Considering the results yields outcomes that contradict prevailing views of the always beneficial role of SSI. In other words, the likelihood of having amplification in structural response due to SSI is large enough that it cannot be readily ignored. This research provides a significant first step towards reliability-based seismic design procedures incorporating foundation flexibility. 相似文献