Journal of Engineering Geology

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Core samples from the sediments of the Dee Estuary were collect-ed from the chosen sites to study the distribution of pesticides in the sediments. The organic compounds were extracted by a microwave sample preparation system from 56 sediment samples and gas chromatography. Mass spectrometry (GC-MS) was employed for the organic compound analysis. Distribution of n-alkanes in the analysed sediments and calculation of their carbon preference index indicate a continental source for the organic compounds in all samples. Different search strategies were applied to find pesticides in the sediments. Maneb was the only pesticide found in the samples. The distribution of Maneb showed a zigzag pattern with depth in all the four studied areas in the Dee estuary, corresponding to the pattern of distribution of total organics. The highest concentration level of Maneb was 16.33 ng/g of sediment at a depth of 14 cm. The distribution of Maneb with depth is attributed to the seasonal application and release to the environment

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In contrast with Mobility Factor (MF) and Risk Assessment Code (RAC) indices, I_R attributes a risk share to metal species bound to reducible and oxidizable phases which are totally neglected in both of the two above-mentioned indices. In other words, besides the absolutely mobile fractions, the potentially mobile ones are also regarded in risk evaluation process elaborated by I_R. The different structure of the newly-developed index may prevent risk level underestimation especially in case where a remarkable percent of bulk concentration is accumulated within reducible and oxidizable phases. The independency of the index value to the bulk concentration makes it possible to discuss the potential risk in different levels of bulk concentration. Furthermore, the index capability in indication of risky pollution, regardless of the pollution source type, may prevent the probable misleading caused by distinct separation of bulk concentration into geopogenic and anthropogenic portion

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Kerman city and its surrounding towns in terms of morphology, consist of a flat alluvial plain of fine silt and clay materials. These sediments have very gentle slope, and constitute the city's main infrastructure. Natural soils generally are structured by passing times due to the influence of environmental factors. Geological factors in Kerman alluviums have caused fine structure after deposition. This paper studies briefly sedimentary basin Kerman, mineralogical and geotechnical properties of the sediments of these areas.semi-qualitative analysis of samples has shown that the mineral deposits in Kerman are mainly illite, chlorite, smectite and calcite. then In order to evaluate the effect of depositional environments and geological history of the engineering properties of the sediments of the Kerman city, A large number of triaxial tests on reconstituted soil moisture greater than LL and different confining pressures, consolidated drained and consolidated undrained is done . In order to evaluate the applicability of soil behavior in normal conditions and the reconstructed curves and stress - strain sensitive soils and soil structure compared with standard sensitivity and then their resistance have been investigated. The results of triaxial tests can be used to interpret the depositional environments and geological history. Comparing the curves of stress - strain in natural and reconstituted samples indicates that in many cases the behavior of intact and reconstituted soils were similar and cementation and soil structure have not been much development. Also Comparison of electron microscopy images of reconstituted and intact samples, not random arrangement of particular structure and soil compaction within the city limits have confirmed. therefore, soils of Kerman are relatively similar by the influence of depositional environments and geological history. these soils have a lot of structure and cementation and are generally compact and strengthening.

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Introduction
Local site conditions considerably influence all characteristics of the ground strong motion including the domain, frequency content, and duration. The level of such an effect could be considered as a function of geometry, properties of the materials embedded in the underlying layers, the site topography, and properties of excitement. Site effect fall into two categories: a) the effect of the surface soft layers triggered by the shear velocity differences between the soil layers and b) the surface and subsurface topography effects that lead to the wave reflection and refraction based on the site geometry, and subsequently enhance the level of amplification.
Since most cities have been constructed in the vicinity of or on sedimentary basins, geotechnical earthquake engineering devotes particular attention to effects of the sedimentary basins. Basin edge curvature deposited with soft soils are capable to trap the body waves and generated surface waves within the deposit layers. Such waves could create stronger and lengthier vibrations than those estimated in a 1D analysis that assumes the shear waves to be vertically propagated.
Although critically important, the 2D effect of the site has not been included in seismic codes and standards of the world. This might be due to the fact that the site effect depends on a number of parameters such as the site geometry, the type of wave excitement, properties of the materials, etc. that in return make it almost out of the question to make predictions about the effect. This study was an effort to compare the responses of four sedimentary basins with hypothetical geometries of rectangular, trapezoidal, elliptical, and triangular shapes in order to examine the effect of the geometrical shape of the basin on its responses and the extent of the response sensitivity to the excitation frequency of the wave. The study assumed the edge to depth proportion to be both constant and equal in all four basins so that the effect of the geometrical shape could be equally examined and compared in all four basins.      
Material and methods
In order to validate the results of the sedimentary basin modeling, firstly, ABAQUS finite element software was used to create a free field motion of a semi-circular alluvium valley in accordance with Kamalian et al. (2006) and Moassesian and Darvinsky (1987).  Then, the results from the model were compared with those from the above mentioned studies. The following descriptions are to present the model in details.
To evaluate the geometrical effect of the sedimentary basin on its response, the authors relied on the software to examine four sedimentary basins with the fundamental frequency (2.04 Hz). The basins enjoyed rectangular, trapezoidal, elliptical, and triangular geometrical shapes with a constant edge to depth proportion (49m to 300m respectively). The implicit method was also applied to perform the dynamic analysis. The materials were all viscoelastic and homogeneous. The soil behavior/treatment model was considered to be of a linear nature.  The Rayleigh damping model was used to specify the damping level. The soil element was a plane strain and SV waves (the Ricker wavelet) were used for seismic loadings in a vertical dispersion. The side boundaries (right and left) of the model were of a combinational type (viscous and free field boundaries); the down side boundary was composed of viscous. To achieve higher levels of wave absorptions, heavy columns were used as the free filed columns.
Next, it was the time to conduct the 1D analysis of the site. Three waves were in use in order to examine the effect of the frequency content of the excitation load on the basin response: 1) a wave with the dominant frequency of 1Hz that was out of the frequency range of all basins (2.04 Hz), a second wave with the dominant frequency of 2Hz that was close to the fundamental frequency of all basins, and a third wave with the dominant frequency of 4Hz. The waves were applied to a 2Dmodel. The results were compared with those obtained from a 1Dmodel in terms of the timing.
Then, the basin responses to all three waves (1, 2, and 4 Hz) were subjected to an individual analysis in order to examine the sensitivity of each basin response to its geometrical shape. Results indicated that while the responses of the rectangular and trapezoidal basins were significantly more sensitive to the excitation frequencies, the elliptical and triangular basins showed more stable behaviors to such frequencies. The final stage of the study was dedicated to examine the site 2D effect during the ground motion.
Results and Conclusions
According to the results of the present study, it could be suggested that the geometrical shape of the sedimentary basin has a significant effect on the responses of the field of seismic waves and that it could result in so different responses from the ones attained after a 1D analysis of the site. In addition, the pattern of the seismic waves’ responses is highly dependent on the geometrical shape and the frequency content of the seismic load. Also, the location where the maximum horizontal acceleration occurs along with the sedimentary basin depends on the excitation wave and varies accordingly. Further, it could be suggested that the site 2D effect results in both considerable amplification and an increase in the length of ground motion.
The results of the 2D analysis showed remarkable differences with their 1D counterparts: a 1.45 larger response for the rectangular basin, a 1.28 larger response for the trapezoidal basin, a 1.22 larger response for the elliptical basin, and a 1.19 larger response for the triangular basin.
With the frequency of 1 Hz where the excitation frequency is out of the basin range (i.e. the excitation frequency is below the lowest frequency of basin), the sedimentary basin did not show any signs of amplification and chaos (unlike two other frequencies); instead, it was a cause for de-amplification.
The frequency of 2 Hz that is subject to resonance resulted in amplifications (absent in 1D analysis) and there are traces of a reduction in the acceleration responses near to the edges of the basins. The proportion of the amplification (in the center of the basins) in 2D to 1D analysis was 1.4 for the rectangular basin, 1.28 for the trapezoidal basin, 1.22 for the elliptical basin, and 1.15 for the triangular basin.
 

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of initial texture and plastic fine content has been investigated. In order to model the different deposition condition four different specimen preparation methods are used. The tests are conducted on sands and its combination with to 25 fine percent using static and cyclic method. Four different specimen preparation methods are used consisting of Dry Funnel Deposition (DFD), Water Sedimentation (WS), Moist Tamping (MT) and Air Pluviation (AP). Each method may be useful to model the behavior of some special deposited soils. For example, DFD is the best method to model the natural deposition of silty sands, while the WS method is suitable for simulating the sands natural deposition in the rivers. MT method is the best method to simulate the behavior of compacted embankments while SD method is suitable to prevent the segregation of particles with respect to other methods like Water Pluviation. Effect of sample preparation methods on the sands and silty sands behavior is investigated to some extent, while the clayey sands are rarely considered. The results show that water sedimentation method, Air pluviation method and Dry funnel deposition method tends to create dilative textures with continuous dilative behavior even in high clay fine content. In contrast, the wet tamping method shows the dilative behavior only for clean sands specimens and increasing fines will results in instability and complete strain softening behavior. In cyclic loading the difference between different methods are less with respect to static loading. It seems that the results of different methods tends to be identical with increasing in fine content. In general, increasing fine content up to 20 percent results in more instability. After that a threshold value can be estimated bout 2 percent, after that the instability becomes less with continuous increase in fines content. The valuable result is that the threshold value is not dependent on the specimen preparation method or initial texture of specimens. 

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