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An empirical method is developed for estimating the load transfer and deformation of drilled, in situ formed piles subjected
to axial loading. Firstly, governing equations for soil–pile interaction are developed theoretically, taking into account
spatial variations in: (a) shaft resistance distribution and (b) ratio of load sharing between the shaft and base. Then generic
load transfer models are formulated based on examination of data from 10 instrumented test piles found in the literature.
The governing equations and load transfer models are then combined and appropriate boundary conditions defined. Using an incremental-iterative
algorithm whereby all the boundary conditions are satisfied simultaneously, a numerical scheme for solving the combined set
of equations is developed. The algorithm is then developed into an interactive computer program, which can be used to predict
the load-settlement and axial force distribution in piles. To demonstrate its validity, the program is used to analyse four
published case records of test piles, which other researchers had analysed using the following three computationally demanding
tools: (a) load transfer (t–z), (b) finite difference and (c) finite element methods. It is shown that the proposed method which is much less resource-intensive,
predicts both the load-settlement variation and axial force distribution more accurately than methods: (a–c) above. 相似文献
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Spatial Topology and its Structural Analysis based on the Concept of Simplicial Complex 总被引：1，自引：0，他引：1
This paper introduces a model that identifies spatial relationships for structural analysis based on the concept of simplicial complex. The spatial relationships are identified through overlapping two map layers, namely a primary layer and a contextual layer. The identified spatial relationships are represented as a simplical complex, in which simplices and vertices, respectively, represent two layers of objects. The model relies on the simplical complex for structural representation and analysis. To quantify structural properties of individual primary objects (or equivalently simplices), and the simplicial complex as a whole, we define a set of centrality measures by considering multidimensional chains of connectivity, i.e. the number of contextual objects shared by a pair of primary objects. With the model, the interaction and relationships with a geographic system are modeled from both local and global perspectives. The structural properties and modeling capabilities are illustrated by a simple example and a case study applied to the structural analysis of an urban system. 相似文献
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Precipitation in the Anatolian Peninsula: sensitivity to increased SSTs in the surrounding seas 总被引：3，自引：3，他引：0
Effects of the increased sea surface temperatures (SSTs) in the surrounding seas of the Anatolian Peninsula on the precipitation it receives are investigated through sensitivity simulations using a state-of-the-art regional climate model, RegCM3. The sensitivity simulations involve 2-K increases to the SSTs of the Aegean, eastern Mediterranean and Black seas individually as well as collectively. All the simulations are integrated over a 10-year period between 1990 and 2000. The model simulations of this study indicate that the precipitation of the peninsula is sensitive to the variations of the SSTs of the surrounding seas. In general, increased SSTs lead to increases in the precipitation of the peninsula as well as that of the seas considered. The statistically significant increases at 95% confidence levels largely occur along the coastal areas of the peninsula that are in the downwind side of the seas. Significant increases do also take place in the interior areas of the peninsula, especially in the eastern Anatolia in winter. The simulations reveal that eastern Mediterranean Sea has the biggest potential to affect the precipitation in the peninsula. They also demonstrate that taking all three seas into account simultaneously enhances the effect of SSTs on the peninsula’s precipitation, and extends the areas with statistically significant increases. 相似文献
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Omer Aziz Tahir Hussain Matee Ullah Asher Samuel Bhatti Aamir Ali 《Marine Geophysical Researches》2018,39(4):491-508
The exploration and production of unconventional resources has increased significantly over the past few years around the globe to fulfill growing energy demands. Hydrocarbon potential of these unconventional petroleum systems depends on the presence of significant organic matter; their thermal maturity and the quality of present hydrocarbons i.e. gas or oil shale. In this work, we present a workflow for estimating Total Organic Content (TOC) from seismic reflection data. To achieve the objective of this study, we have chosen a classic potential candidate for exploration of unconventional reserves, the shale of the Sembar Formation, Lower Indus Basin, Pakistan. Our method includes the estimation of TOC from the well data using the Passey’s ΔlogR and Schwarzkofp’s methods. From seismic data, maps of Relative Acoustic Impedance (RAI) are extracted at maximum and minimum TOC zones within the Sembar Formation. A geostatistical trend with good correlation coefficient (R2) for cross-plots between TOC and RAI at well locations is used for estimation of seismic based TOC at the reservoir scale. Our results suggest a good calibration of TOC values from seismic at well locations. The estimated TOC values range from 1 to 4% showing that the shale of the Sembar Formation lies in the range of good to excellent unconventional oil/gas play within the context of TOC. This methodology of source rock evaluation provides a spatial distribution of TOC at the reservoir scale as compared to the conventional distribution generated from samples collected over sparse wells. The approach presented in this work has wider applications for source rock evaluation in other similar petroliferous basins worldwide. 相似文献
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Deniz Bozkurt Ufuk Turuncoglu Omer Lutfi Sen Baris Onol H. Nuzhet Dalfes 《Climate Dynamics》2012,39(1-2):207-225
The outputs of three GCMs, ECHAM5, CCSM3 and HadCM3, are downscaled for the eastern Mediterranean–Black Sea region for the period 1961–1990 using a regional climate model, RegCM3, to assess the capability of these models in simulating the climatology of the region. In addition, the NCEP/NCAR Reanalysis data are also downscaled for the same period to display the performance of the regional climate model for the same region, which constitutes a relatively complex terrain and rich variety of climates. The gridded observational dataset of CRU is primarily used in the evaluation of the models, however, a regional dataset, which is based on a relatively dense gauging network, is also used to see how it affects the performance measures of the models. The reanalysis simulation indicates that RegCM3 is able to simulate the precipitation and surface temperature as well as the upper level fields reasonably well. However, it tends to overestimate the precipitation over the mountainous areas. All three GCM models are found to be highly skilled in simulating the winter precipitation and temperature in the region. The two models, ECHAM5 and HadCM3, are also good at simulating the summer precipitation and temperature, but the CCSM3 simulation generates dryer and warmer conditions than the observations for the whole region, which are most likely a result of the dryness in the upper levels of the original outputs. The use of the regional observational dataset does not necessarily improve the pattern correlations, but it yields better match between the modeled and observed precipitation in terms of variability and root-mean-square difference. It could be said that the outputs of these GCMs can be used in the climate change downscaling and impact assessment studies for the region, given that their strengths and weaknesses that are displayed in the present study are considered. 相似文献
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