Engineering and Technology Journal

Batter piles or raker piles are the piles driven in the soil at an inclination with the vertical to resist inclined forces or large lateral loads. Battered piles are widely utilized to support offshore buildings, towers, and bridges since these structures are risky due to the exposure to overturning moments resulting from winds, waves, and ship impact. This paper used a three-dimensional finite element analysis using PLAXIS 3D software to study the effect of several variables that affect the behavior of batter piles in a group under pullout loads. The study is conducted on a steel pipe pile model embedded in a dry sandy soil with three different relative densities (loose, medium, and dense sand) at different inclination angles and three embedment ratios L/D of 25, 37.5, and 50, respectively. The finite element model was carried out on a pile group of 2×1 with different configurations. The numerical results indicated that for all pile configurations, the pullout capacity of the batter pile group increased when the embedded ratio and relative density increased, and the maximum value was attained at a 20° batter angle. Furthermore, batter pile groups with BB (group with two battered piles) configuration of (-20°, +20°) gave a high resistance to the pullout load compared to other configurations of the pile group. In addition, pile Groups with battered piles marked the resistance to the pullout load more than pile groups that contain only the vertical piles

The use of biochar as a soil amendment has been the focus of many studies. It is believed to improve soil characteristics and increase crop yields. Still, a diverse range of feedstocks needs to be researched and converted to biochar for environmental purposes. To achieve sustainable biochar, it is favorable to be derived from residues available locally, and particularly interesting are those that have been turned to biochar near the application area. This study investigates the effects of locally date palm-derived biochars produced at four different temperatures (250, 350, 450, and 550oC) for 60 minutes on soil physicochemical properties, mainly; pH, bulk density, and total nitrogen availability. The biochar application ratios were 5% and 10% by weight to each soil sample. The soil was gathered from a local farm near Al-Kargoulia, textured as clay loam, and had a total nitrogen content of 25 mg/kg. From mixing through incubation, the experiment lasted 30 days. Biochars produced at (250-350oC) have a minor impact on soil characteristics, whereas biochar produced at (450-550oC) had a higher effect on soil properties. Bulk density was decreased due to biochar’s high porosity (up to 90%), while pH increased from 7.23 to 8.5. In contrast, nitrogen was affected highly and increased to 32.33 mg/kg.

In recent years, Open Graded Friction Course OGFC is becoming more common in some countries. It is applied to improve surface frictional resistance, minimize hydroplaning, reduce water spray, improve night visibility, and lower pavement noise levels. These functions are carried out primarily by removing water from the pavement surface during a period of rain. Also, it has many disadvantages which as poor resistance to permanent deformation, low fatigue strength, high stripping, and moisture susceptibility. The paper aims to investigate the probability of using Cellulose Fiber (CF) as a modifier to improve the properties of OGFC asphalt mixture. In this research, one type of asphalt grade (40-50) and one gradation (19 mm Maximum Aggregate Size MAS) were used. Three percentages of CF (2%, 4%, and 6%) were added to asphalt cement to obtain the modified mixtures. Optimum asphalt content was selected by evaluating the following criteria: air voids content, asphalt drain down, abrasion resistance, and permeability. Several laboratory tests such as Indirect Tensile Strength (ITS), moisture susceptibility, Marshall stability, and flow were evaluated for modified samples, and their results were compared to the original open-graded asphalt mixture. The outcomes indicated that cellulose fiber greatly enhanced the mechanical properties of OGFC mixtures, increasing moisture damage resistance by 19.4%. Furthermore, Marshall stability improved by 38.92 % as the abrasion loss is decreased by 15.85% with adding of CF for aged samples.

The coefficient of lateral earth pressure at rest (K0) explains the connection between the effective vertical and lateral stresses. Geotechnical engineers have studied K0 for many years for its being a key element in the designs and analysis of various geotechnical problems such as slope stability, piles, and earth retaining structures. Moreover, K0 has played a critical phase in any numerical study of the soil-water combined geotechnical boundary value issues requiring parametric stress-strain time formulations During the previous few decades. A modified apparatus consisting of a standard Oedometer equipped with Force Sensitive Resistance (FSR) is used to investigate the value of lateral pressure (????????ℎ
′ ) due to the vertical stress. The Oedometer test is carried out on three samples with different organic contents, with the K0 values obtained from each sample; empirical equations were also used to estimate K0 values for comparison purposes. From the analysis of the results, it can be stated that the K0 value is inversely proportional to the organic matter percent in the soil. It varies from 0.6125 in soil with 25.1% organic percent to 0.76 at a percent of 9.8%. The Force Sensitive Resistance (FSR) technique's performance is practical enough for estimating lateral earth pressure at rest (K0) of normally consolidated organic soil with many advantages; it is far less time-consuming and has a low operating cost than the traditional K0 estimate methods. Furthermore, K0 decreases with the increase of organic content.

This paper investigates the impact of the plant fly ash (dry tree leaves) addition on the geotechnical properties of the landfill soil, where an engineering laboratory landfill simulating a real landfill was manufactured. Two percentages of plant fly ash (10% and 15%) were used to reduce or prevent the penetration of heavy metals resulting from the decomposition of landfill waste into the soil and conducting laboratory tests such as the Atterberg test, specific gravity test, compaction test, permeability test, SEM test, and heavy metals analysis. The results of laboratory tests indicate a decrease in the plastic limit and the liquid limit with the addition of plant fly ash, as well as a decrease in the specific gravity and a decrease in dry unit weight with an increase in the need for water content when adding plant fly ash. In contrast, the permeability increased with the addition of plant fly ash. In the most important laboratory test, which is the chemical analysis of soil metals, the soil improved with plant fly ash gave results indicating a lower level of metals pollution at depths of (10 cm, 20 cm, and 30 cm) of soil layer compared to natural soil. The analysis was conducted on 7 basic pollutants (cadmium, copper, iron, Manganese, Zinc, Chromium, and lead), where the percentage of pollutants decreased in improved soil compared to natural soil under the same conditions by (50%, 74%, 62%, 68%, 60%, 68%, and 55%) respectively.

Dyes are an essential group of organic pollutants with a long history of harming aquatic life and humans. Prior to disposal, polluted dye wastewater must be adequately treated to prevent adverse impacts on persons and the environment. Although there are several techniques for dye removal, most of them share a similar drawback: they generate secondary pollution to the environment. Membrane separation is highlighted in this article because it is one of the most efficient dye removal techniques available nowadays due to its high removal capacity, ease of operation, and clean water generation. Polymeric membranes are frequently used in membrane-based separations because of their greater flexibility, ease of pore formation process, and lower cost than other membrane materials. Although polymeric membranes are preferable materials for membrane production, they are usually hydrophobic and, hence, sensitive to fouling. Therefore, much research has been done to modify the polymeric membrane. More recently, metal nanoparticles (NPs) have been introduced to the polymer matrix to minimize fouling potential and enhance membrane performance. This study describes several polymeric membranes utilized in dye separation that have been modified using nanomaterial. Also, the study illustrates how adding these components affects the membranes' performance in rejecting the dye. Additionally, it highlights the importance of membrane-nanomaterial interactions and the effect of these materials' additions on membrane performance over time.

This research aims to study the benefit of using fibers made from waste materials in concrete and evaluate the ability to use these fibers as a substitute for commercial fibers. Different aspect ratios of alternative fibers formed from cut steel tied wire waste were utilized. This material is selected because of its low price and wide availability. Two concrete mixes with 15% waste crushed clay brick coarse aggregate reinforced with different volume fractions of 1.0 and 1.5% and an aspect ratio of 40 were prepared. Also, three concrete mixes reinforced with a hybrid aspect ratio of 40 and 65 of tied wire waste steel fibers (TWWSF) with different volume fractions of 1.0% and 1.5% were prepared. The compressive, splitting tensile, flexural strengths, and ultrasonic pulse velocity (UPV) of all prepared concrete mixes were tested. The results illustrate that the inclusion of tied wire waste steel fibers significantly enhances the strength of concrete with 15% waste crushed clay brick coarse aggregate, and high-performance concrete with compressive strength of up to 85 MPa can be produced. The enhancement in compressive, splitting, and flexural strengths were 29%, 42.8%, and 38%, respectively, for concrete reinforced with a fiber aspect ratio of 40 and volume fraction of 1.5%. In comparison, for the same volume fraction, the percentage was 22%, 48%, and 44%, respectively, for equal content of hybrid aspect ratio of 40 and 65.

Increasing the cross-sectional area of the piles or adding wings to the piles are two strategies for increasing the bearing capacity of the piles to resist lateral stresses. Small and full-scale finite element models were used to investigate the effect of adding the wings on the laterally loaded pile bearing capacity in this study. Four embedded ratios (4, 6, 8, and 10) were used with various wing dimensions and numbers. The results showed that adding wings to the pile increases the resistance to lateral loads and reduces the lateral displacement significantly. +To achieve the highest lateral resistance, the wings should be fixed parallel to the lateral load applied to the pile and close to the pile head. The ultimate lateral applied load is proportional to the rise in relative density. The lateral pile capacity was increased by 16.5%, 18.4%, and 33% in dense, medium, and loose sand, respectively, at the same length to diameter ratio (L/D). Increasing wing length improves lateral capacity significantly. At a failure, the lateral pile capacity was 18% and 8.5 % for Lw, equal to 112 mm and 56 mm, respectively. Another study's purpose was to determine how increasing the number of wings affected pile resistance. The lateral pile capacity at failure was increased by 9.8 % for two wings, 18.4 % for three wings, and 18 % for four wings.

The temperature and stress caused by the load can be cited as two main parameters leading to breakage in asphalt pavement, especially rutting (permanent deformation). So, to reduce the problems of rutting of roads, several actions have been taken, including improving pavement quality and the structure design methods. The increase in the attention of respective engineers in the last few years to modify and improve the asphalt performance through providing different types of additives and replacing the raw materials of asphalt mixture with recycled materials to improve the environment and reduce the cost of modified pavement mixture. This study discussed the use of low-density waste polyethylene as an asphalt modifier in percentages of (2, 4, and 6) % by the weight of asphalt and their impact on the performance of asphalt mixtures at high temperatures. This study showed that using plastic waste (low-density polyethylene) as a bitumen modifier improved the performance of asphalt mixtures at different high temperatures. This was achieved by reducing the rut depth by (80.5) % and (82.3) % at temperatures of 50 C and 60 C, respectively, using low-density polyethylene waste at an optimum value of about 4% by weight of asphalt in addition to enhancing the Marshall stability by using this percentage of polymer.

Introducing nanotechnology to the pavement industry witnessed a great interest due to the proven benefits of nanotechnology in various scientific fields. However, the reduction in the binder's characteristics might be disadvantageous to the durability of the recycled mixture, making it more susceptible to external factors such as moisture. Therefore, using nanotechnology is expected here to treat this issue. The goal of the current paper is to report on the influence of the nano-clay montmorillonite (MMT) powder (MMT k10) on the resistance to moisture in the hot recycled mixtures or the Reclaimed Asphalt Pavement mixtures (RAP mixtures). In this work, different proportions of rejuvenated RAP were employed. These proportions are 30, 40, and 50% as a percent of the overall weight of the mix. The percentages were mixed with a nano-modified neat binder with (0, 1, 3, and 5)% nono-clay MMT as a proportion of the bitumen’s weight. Two types of mixtures are prepared and used in this paper: nano-modified RAP mixtures and unmodified RAP mixtures. On both types of mixtures, the compressive strength test, the index of retained strength (IRS), the indirect tensile strength tests (ITS), and the tensile strength ratio (TSR) were carried out to compare and

The types of post-setting curing and high range water reducing (HRWR) admixture used in Ultra-High-Performance Concrete (UHPC) mixtures play significant roles in determining their rheological and mechanical properties. This study compares the performance of three types of HRWR admixtures commercially available when added to UHPC mixtures under three different curing regimes. Mixtures made with the different superplasticizers were evaluated for their flow, 45mins flow retention, and setting time as fresh mix properties. Compressive strength was also tested for each mixture after 3, 7, and 28 days of curing at the investigated various curing regimes. Sika Viscocrete 180GS produced the highest mixture flow and flow retention levels with a 241 mm flow and 93.7% flow retention. Sika Viscocrete 168-1 produced the best results of setting time with 3 hours as compared to 12 hours with Sika Viscocrete 180GS. Using Hyperplast PC-202, the required 150 MPa compressive strength was secured as early as 3 days of curing with a 48hrs-90ºC curing regime. Using the same HRWR admixture, compressive strength values slightly lower than 150 MPa were reached after 7-28 days when the 72hrs-60ºC regime was adopted. The last curing regime was recommended for producing architectural UHPC units to minimize the delayed formation of ettringite.

The harnessing of glass waste, which is slow to decompose and has high recycling costs, is in the interest of supporting and stimulating a balanced construction pattern that is interdependent on the living environment. Consumable food and drink bottles are one of these forms of waste that can be calibrated to meet desired specifications. Controlled low-strength materials with low and deliberate strength for future excavation have highly desirable rheological properties, active hardening, and zero or rare separation of materials can be maintained with waste glass substitution. In this study, an experimental evaluation was commenced to estimate the practicality of waste glass (fine and coarse powder) by replacing fly ash and natural sand with it to control low-strength materials. A sum of seven slurry blends was intended by employing several ratios (10%, 30%, and 50%) of fine and coarser waste glass. Some characteristics of plasticity and hardness were observed, such as fine glass decreased flowability. In contrast, coarser glass decreased dramatically, exceeding the minimum limit of 20%, which necessitated the use of superplasticizer in a proportion that corresponds to the increase in the replacement. Unit weight slightly increased with fine glass substitution, but in the Coarser substitution, a steady decrease occurred. The compressive strength of 28 days in fine glass replacement is less than the reference mixture, but it exceeded it at 90 days. A mixture incorporating coarse waste glass was higher at 28 days and developed at 90 days.

Land Surface Temperature (LST) is a critical parameter for water resources and hydrology investigation. Weather ground stations provide a continuous dataset on the LST. However, some stations rely on discrete events data, which shows limited capabilities to monitor diurnal and annual changes in LST. Remote Sensing technology provided much valid information by using Moderate Resolution Imaging Spectroradiometer (MODIS) to cover LST variations in Iraq. This study aims to analyze LST variation based on MOD11C3 Data with weather ground measurements stations for the different topography periods between 2000-2020. Different statistical parameters were used to validate LST results, including RSME; NSE; R2, and Parson Correlation. The results indicate agreement between MODIS and ground measurement stations during the winter season. The values ranged: RSME (close to zero); NSE (0 to 1); R2 (between 0.5 and 1), and Parson Correlation (between 0.51 to 1).In spring, the values ranged: R2 (between 0.5 and
1) and Parson Correlation (between 0.51 to 1). As the temperature rises during
seasonal changes, the congruence in the four statistical indicators begins to decline
dramatically. However, Baghdad, Basra, and Mosul stations still appear in good
agreement, which is the validity of the data issued by MOD11C3. The finding
presented in this research shows that the results of the LST by MOD11C3 are in
good agreement and acceptable despite in various topographies of the ground
stations.

Keeping the average global temperature rise below the 1.5oC value over the pre-industrial era requires all hands to be on deck. The energy sector, transportation sector, and the agricultural/land use segment are significant contributors to greenhouse gas emissions responsible for global warming. While there is an ongoing campaign for tree planting to reduce atmospheric CO2 volumes, it is imperative to note that the population explosion in some climes is pushing up the demands for land. The housing deficit in Nigeria is more than twenty million units. Building units are required to bridge the deficit; hence, an attendant forest cover loss. The study aims to propose an eco-sustainable means of bridging the shortfall. Sticking to the practice of a building unit per plot will lead to a CO2 absorption potential loss of about 1.11 billion tonnes over twenty years. However, building more units per plot will be a respite. Ten building units per plot can push down the figures to 0.1115 billion tonnes over the same period and was the best for the considered scenarios. The study showed that the loss of CO2 absorption potential from forest cover loss could be minimized by building more housing units per plot of land.

Three-dimensional (3D) real-scale models delivered from digital photogrammetric techniques have rapidly increased to meet the requirements of many applications in different fields of daily life. This paper deals with establishing a 3D real-scale model from a block of images (18 images) captured using a Canon EOS 500D digital camera to cover a test field area consisting of 90 artificial target points, 25 of which are ground control points (GCPs). At the same time, the remains are checkpoints (CPs). The analytical photogrammetric processes, including the calculation of interior orientation parameters (IOPs) of the camera during the camera calibration process and exterior orientation parameters (EOPs) of the camera in each capture. The model's object space (ground) coordinates are calculated simultaneously based on the collinearity equation using the bundle block adjustment method (BBA). Assessment and validation of the accuracy of the results is an important task in this study that was implemented to determine and analyze the errors of 3D coordinates through linear regression analysis (LRA). Root mean square error (RMSE) is the statistical parameter used in the statistical analysis of results. The standard error is another statistical parameter used to evaluate the accuracy of camera locations and rotation angles (EOPs). The total RMSE (RMSE) xyz of GCPs is ± 2.530 mm, while the total RMSE (RMSExyz)
of CPs is ± 2.740 mm. The overall accuracy of the work is 5.000 mm.

Global warming induces to increase of greenhouse gases in the atmosphere and plays a crucial role in determining the future trend in climatology and hydrology of a watershed. This paper aims to investigate the implications of global warming on future climate and its consequents on streamflow of the Adhaim River Basin (ARB). For this purpose, the Long Ashton Research Station-Weather Generator (LARS-WG) and Soil and Water Assessment Tool (SWAT)-Based models were implemented. The climate and hydrologic records for the period 1990-2019 were used as a Reference Period (RP) and projected to 2080 under Representative Concentration Pathways (RCPs 2.6, 4.5, and 8.5) and five Global Climate Models (GCMs). The results show that the region of ARB tends to become hotter and drier with an increase in mean temperature by 1.2, 2.9, and 4.6 °C under the considered RCPs, respectively. However, precipitation tends to decrease from 366 mm/y in RP to 320.2, 302, and 300.5 mm/y by 2080 under the considered RCPs. Consequently, the streamflow will decrease to about 28, 26, and 24 m3/s by 2080 under the considered RCPs, respectively, compared with 28.96 m3/s in RP. Therefore, adaptation strategies are highly recommended to alleviate the negative impacts of climate change, and the implications of climate change on groundwater, water demand, and adaptation plans should be investigated in future studies

Helical piles are a kind of foundation that can withstand compression, tension, and lateral stresses. However, this kind of pile was utilized extensively globally for almost 25 years. Its behavior, particularly in Iraq, is uncertain and frightening. The current research used the finite element technique to analyze this kind of pile. The helical pile geometry was suggested to be modeled using the finite element method using the computer software Plaxis 3D The soil used is medium sandy soil. Additionally, parametric analyses were conducted. The primary parametric research examines the impact of helix number, helix spacing, helix diameter, and helix configuration under cyclic load. The main results are more helices in a pile, the lower the amplitude of settlement (in the direction of z) compared to a pile without helices. As a result, the amplitude of settlement in the case of two helices decreased by 81.6 %, while the amplitude of settlement in the case of three-helix decreased by 77.74 %. In the case of three helices, the higher spacing between the helices, the lower the value of the amplitude of settlement (in the direction of z). The effect of the number of helices in the hardening soil model is more than the effect of the number of helices in the Mohr-Coulomb. As a final result, increasing the number of helices in a pile has a more significant effect in reducing the amplitude of settlement than increasing the between the helices.

This study investigates the driver behavior of a certain number of drivers using a questionnaire method. The questionnaire contains a part of drivers' demographics, including age, gender, and the type of transportation most used by the drivers. It was divided into three parts. Each part deals with a specific type of road in Baghdad City: multi-lane, two-lane, and local. The questions were about the number of times they drove the vehicle on each type of road, the speed at which they drove the vehicle and did not cause accidents, the distance traveled during the last week on each type of road, and the number of times the speed limit was exceeded. The most prominent reasons for increasing the speed of drivers were also indicated, and solutions were suggested to reduce the speed of drivers. The results show that the driver's age was considered an important factor in the driver’s behavior. It was found that the older the driver, the more committed he was to the proposed speed limits for each type of road. In addition, spreading public awareness about speed reduction to reduce violations and accidents is vital.

In this paper, the self-sensing properties of cementitious composites under compressive loads were investigated by utilizing hybrid functional fillers, which are responsible for creating an electrical network that is used to build the self-sensing capability within the traditional cement-based mixtures. Most of the previous works depict the self-sensing capability with the aid of one type of functional fillers or fibers. The present paper attempts to utilize two types of functional fillers, representing a gap filling within the subject. Four hybrid proportions of Graphite (G) (wt.%) and carbon fibers (CF) (vol.%) were introduced. These are (0.5, 1.0), (1.0, 0.75), (1.5, 0.50) and (2.0, 0.25) respectively. In addition to carbon-based materials, polypropylene, polyolefin, and steel fibers are used as reinforcing fibers. One type of fiber was utilized in each manufactured mixture with a constant rate of 2% by volume of the mixture. A plain mixture without functional fillers has also been manufactured. The samples were non-destructively tested by an ultrasonic device before a uniaxial compression test was performed. To verify the self-sensing properties of the manufactured samples, the electrical resistance of the samples was recorded during load application each second. The self-sensing behavior was better for mixtures containing high dosages of graphite with respect to the fractional change in electrical resistivity (FCER). Steel and polyolefin fibers showed good results in terms of compressive strength behavior. However, polypropylene fibers showed the lowest compression strength among all types of reinforcing fibers used.

In the current work, an analytical solution for static bending analysis of the thick rectangular plate structure was obtained using three-dimensional plate theory. First, the energy equation was formulated from the static elastic principles and transformed into a compatibility equation through general variation to get the slope and deflection relationship. The solution of the compatibility equation gave rise to the exact polynomial deflection function. In contrast, the coefficient of deflection and shear deformation of the plate was obtained from the governing equation through the direct variation method. These solutions were used to obtain the characteristic expression for analyzing the displacement and stresses of a rectangular plate. This formula was used for the solution of the bending problem of rectangular plate support conditions of two clamped edges, one free edge, and a simply-supported edge (CCFS). The result of the deflection and stresses decreases as the span-thickness ratio increases. More so, the aspect ratio effect of the shear stress of isotropic plates is investigated and discussed after a comparative analysis between the present work and previous studies. The result shows that the present study differs with RPT) of assumed deflection by 2.7%, whereas exact 2-D RPT by 1.9%. This shows the efficacy of the exact 3-D plate theory for rectangular plate analysis under CCFS support and loading condition.

Renovation of the naturally existing area for ecotourist and investments that attracting site-visitors, picnickers and tourists for Iraq, Kurdistan Region, Sulaimani need to promote a reliable decision-making technique so as to raise the level of the tourist-based economy. In this study, the most available public well known and recognized tourist and picnic area by the people and associated governmental directories were studied and assessed for their tourism reliability and capacity. The study area of this research covered tourist area and they were forty-three (43) locations and all the related data collected, analyzed and categorized as main and sub-main criterions. The analytical hierarchy process (AHP) has been used for assessment of that area which was ranked accordingly from the highest to lowest capacity and efficiency’s reliability of tourism. The opinion of experts from tourism agencies, related tourism officials and people from the local area also taken into consideration and translated and used in the AHP assessment tool. Weight factors of the main and sub-main criterions were founded and analyses for their inconsistency. The main criterions and their pairwise weights as per AHP assessment were climate, available green area, root distance, easy of transportation, essential requirements, entertainment tools, provided security and healthcare, respectively.

This paper implemented an HEC-RAS-based steady two-dimensional hydrodynamic model to evaluate the hydraulic characteristics and Sediment Transport Capacity (STC) of the Makhool-Samarra Reach of the Tigris River, where this part is not already investigated. This model was prepared with the aid of topographical surveys, hydraulic measurements, and laboratory tests, as well as recorded data. The main findings show that the flow velocities within most of the studied reach are considered high compared to the local and worldwide flow velocity ranges in natural rivers. Also, the Toffaleti sediment transport function with the Van Rijn fall velocity and the effective depth-to-width computation methods are the most compatible and suitable methods for computing the Sediment Transport Potential (STP) in the studied reach. With the maximum flow, the computed STP was less than the average (5.7×106 tons/day) in 45% of the reach length, where the maximum STP is 8.7×106 tons/day. However, with the minimum flow, the STP intermittently fluctuates below the average (0.2×106 tons/day) in 48% of the reach length, where the minimum STP is 0.14×106 tons/day. Generally, these STPs are little more than the Tigris River in Mosul and much higher than that in Baghdad. Also, these STPs are considered high on a global scale, especially during high flow. Medium gravel is the larger grain gradation class that can be transported. It constitutes less than 0.00005 % of the STP. Furthermore, the STC computations clearly show that the suspended sediment is the dominant part of the STC and the bed material constitutes less than 0.002% of the STC of the total load. However, most of the STC concerns the clay and very fine silt.

Pile foundation bridges are structures extending in the middle of the sea, so they are subject to currents, waves, and earthquake forces. This article presents a hybrid simulation that was used with input excitations of different current velocities, wave properties, and earthquake amplitudes to assess the non-linear dynamic behavior of pile foundation bridge piers. Based on the interface between MATLAB and ABAQUS software, the general formulations of fluid-structure interaction (FSI) under combined current-wave and earthquake loads are derived. Hydrodynamic and earthquake loading is consistently introduced by creating synthetic time histories of combined current-wave actions and spatially variable ground motion. The behavior of the dynamic model of a deepwater pile foundation bridge for the Songhua River in northeast China was adopted as an example of the study. The accuracy of the created model was verified using prior experimental and analytical computations. It is demonstrated how both linear and nonlinear dynamic behavior performs at various water depths under coupled current-wave-earthquake loading conditions. Revealing interesting aspects, particularly in terms of relative displacement, acceleration, shear, and moment response are shown. The results showed that the hybrid model is an efficient of simulating accurate predictions of the hydrodynamic pressure during earthquake actions for structures in coastal areas.

Composite columns are often used in constructing high-rise structures because they can reduce the size of a building's columns while increasing the usable area in the floor plan. This research aimed to develop a nonlinear 3D finite element analysis model using the ABAQUS, version 6.13-4, of various round composite column designs with varied multi-skin of tubes for solid and hollow columns subjected to various eccentricity loads (90, 180 mm). Extended data to another 12 specimens of composite columns by numerical method, based on six references experimental data of composite columns. The results of ABAQUS data in this study show that; increasing eccentricity for applied loads causes a decrease in loads to fail for composed columns. The ultimate load of hollow composite sections under eccentricity is lower than solid composite sections under different eccentricity loads. Also, the same results indicated fort eccentricity loads. The same results indicated an increased number of steel layers. The stiffness of concrete is greatly influenced by its strength. When the concrete strength rises, the stiffness of the composite column rises as well. The ratios of concrete compressive strength values according to the reference column (CC1S00 with fc’=31.96 MPa) were (-4.4, 3.1, and 6.5) percent for the specimen (CC1S00) with (fc’=25, 35, and 40) MPa, respectively. The method utilized is in the nonlinear analysis, and the finite element results are in good agreement with the experimental results