Civil Engineering / İnşaat Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/13

Browse

Search Results

Now showing 1 - 3 of 3
  • Conference Object
    Upscaling Surface Flow Equations Depending Upon Data Availability at Different Scales
    (Springer Verlag, 2003) Tayfur, Gökmen
    St. Venant equations, which are used to model sheet flows, are point-scale, depth-averaged equations, requiring data on model parameters at a very fine scale. When data are available at the scale of a hillslope transect, the point equations need to be upscaled to conserve the mass and momentum at that scale, Hillslope-scale upscaled model must be developed if data are available at that scale. The performance of the three models applied to simulate flows from non-rilled surfaces revealed that the hillslope-scale upscaled model performs as good as the point-scale model though it uses far less data. The transectionally-upscaled model slightly underestimates the observed data.
  • Article
    Citation - WoS: 8
    Citation - Scopus: 8
    Estimation Groundwater Total Recharge and Discharge Using Gis-Integrated Water Level Fluctuation Method: a Case Study From the Alasehir Alluvial Aquifer Western Anatolia, Turkey
    (Springer Verlag, 2020) Şimşek, Celalettin; Demirkesen, Ali Can; Baba, Alper; Kumanlıoğlu, Ahmet; Durukan, Seda; Aksoy, Niyazi; Tayfur, Gökmen
    The estimation of groundwater recharge is an essential process for hydrogeological study. Realistic determination approach is crucial for assessing groundwater potential in an aquifer system and estimating of groundwater levels and/or changes in dry periods. Based on these matters, we employ a GIS-integrated groundwater level fluctuation method to determine the groundwater recharge for a hydrological period in the Alasehir alluvial aquifer (W. Anatolia). The method basically takes into account both increasing and decreasing of the groundwater levels due to the recharge and discharge mechanisms in the aquifer. In this study, 16 pumping and monitoring wells were drilled with a total depth of 1300 m, and water level data loggers were installed into the monitoring wells to determine the groundwater level changes. The spatial distribution of the monthly groundwater level change map was multiplied by the aquifer storage distribution map and then the accurate water volume is calculated by using the 3-D spatial analysis. According to our evaluation in the aquifer, positive volume change of the groundwater is 187 hm(3) in a year, which is considered as a recharge value of groundwater. It is concluded that the GIS-integrated water table fluctuation method gave rise to estimate the total recharge amount of the groundwater in the Alasehir aquifer. The total groundwater recharge indicates that total inflow in the aquifer from precipitation, leakage from surface water and irrigation waters. It can be stated that the recharge estimation of groundwater in a surficial aquifer, like the Alasehir aquifer, is fairly easy using the GIS-integrated water table fluctuation method.
  • Article
    Citation - WoS: 16
    Citation - Scopus: 38
    Time-Dependent Physicochemical Characteristics of Malaysian Residual Soil Stabilized With Magnesium Chloride Solution
    (Springer Verlag, 2016) Latifi, Nima; Rashid, Ahmad Safuan A.; Ecemiş, Nurhan; Tahir, Mahmood Md; Marto, Aminaton
    The effects of non-traditional additives on the geotechnical properties of tropical soils have been the subject of investigation in recent years. This study investigates the strength development and micro-structural characteristics of tropical residual soil stabilized with magnesium chloride (MgCl2) solution. Unconfined compression strength (UCS) and standard direct shear tests were used to assess the strength and shear properties of the stabilized soil. In addition, the micro-structural characteristics of untreated and stabilized soil were discussed using various spectroscopic and microscopic techniques such as X-ray diffractometry (XRD), energy-dispersive X-ray spectrometry (EDAX), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) surface area analysis. From the engineering point of view, the results indicated that the strength of MgCl2-stabilized soil improved noticeably. The degree of improvement was approximately two times stronger than natural soil after a 7-day curing period. The results also concluded the use of 5 % of MgCl2 by dry weight of soil as the optimum amount for stabilization of the selected soil. In addition, the micro-structural study revealed that the stabilization process modified the porous network of the soil. The pores of the soils had been filled by the newly formed crystalline compounds known as magnesium aluminate hydrate (M-A-H).