Column Elements Research Articles

SUGGESTIONS FOR IMPROVEMENTS IN TIMBER PORTAL FRAME DESIGN WITH SEMI-RIGID KNEE JOINTS

Timber portal frames assembled on the construction site are the most suitable solution from the point of view of limitations of transportation options. However, the connections of the rafters and columns assembled at the construction site in the knee joints, using bolts, show a certain tendency to show plastic deformations under load. In addition, the transmitted shear forces at the knee joint form different angles with the fiber direction in the rafter and column elements. Service experience of timber portal frames shows that the vertical displacement of the apex point increases, also cracks appear in the rafter elements near the knee joints over time. Unfortunately, code design formats do not present specifications for timber structures incorporating L-shape joints with mechanical fasteners. This article presents the results of studies that confirm the need to supplement the design rules for wooden portal frames. It is recommended to implement the rotational spring constant when define rigidity of L-shape joints for RFEM model of structure. The Hoffman failure criterion has been chosen as the most appropriate of the known ones for evaluating the crack resistance of structural wooden elements, because this criterion includes more important specific properties affecting the development of plastic deformations and the formation of cracks in wood.

A shear–flexure interaction model for column elements with biaxial loading

This research develops a 3D macroscopic model to capture the shear and flexural behavior of square and rectangular reinforced concrete columns under biaxial lateral loads. This efficient-shear-flexure-interaction (E-SFI)–BIAXIAL model, based on the E-SFI two-dimensional macro model, reformulates the materials and elements to a 3D domain. Reinforced concrete prisms with three-dimensional behavior are incorporated using a rotating-angle approach and calibrated expression of the two-dimensional model to calculate the horizontal strain in each orthogonal direction (ɛx and ɛz). This approach reduces the number of iterative processes and analysis time. Model validation employed an extensive database of 56 reinforced concrete column tests with shear failure under cyclic biaxial loading conditions, 41 square and 15 rectangular, as reported in the literature. The validation demonstrated that the model accurately captures the hysteretic response and shear failure mode of the tests. The results are verified against the experimental data regarding the load–displacement response and the contribution of flexural and shear displacements. The model’s estimated shear strength agreed well with experimental data, with average ratios of measured to calculated maximum shear strength of 0.91 and 0.95 for square and rectangular columns with coefficients of variation of 0.078 and 0.12, respectively. The onset of strength degradation was also compared, achieving average ratios of the measured to calculated drift for square and rectangular columns of 1.02 in both cases, with coefficients of variation of 0.32 and 0.4, respectively. Furthermore, the normalized biaxial shear strength results from the experimental tests and the model fit the circular interaction curve and validate the proposed ACI 318-19 code provisions to capture the biaxial shear effect through a trilinear curve.

Steel savings in an industrial building column with account for effect of crane girder stiffness

Introduction. Construction science always seeks to save materials, including in the design of steel frameworks. Currently, in modern construction standards, structural analysis of frameworks for industrial buildings, namely their columns, is carried out without considering the stiffness of the crane girder which receives the load from the overhead crane. However, this factor can give a certain economy of metal, since the stiffness of crane structures directly affects the stability of columns of industrial buildings, and therefore the metal consumption of the framework.Aim. To achieve savings of steel due to taking into account the effect of crane girder stiffness on the stability of an industrial building framework.Materials and methods. For these purposes, the authors of the paper used classical methods of structural mechanics. A programmed cyclic algorithm of the Mathcad software was used to find the critical forces and effective length coefficients at various stiffnesses of the column elements. Columns of an industrial building are usually two-member. Given that, its structural design is twice statically indeterminate by the deflection method. The bearing capacity of an industrial building column is found by deriving the critical force, which is determined from the equation obtained by setting equal to zero the stability determinant consisting of the coefficients of the linear equation system by the deflection method. In addition, the effective length coefficient for the upper and lower parts of the column is determined. The paper compares the results obtained with the scheme without taking into account the crane girder.Results. Considering the effect of the crane girder stiffness enabled the material consumption of the column to be reduced by 30 %. Critical forces and effective length coefficients were found at various stiffnesses of the column elements, using a programmed cyclic algorithm of the Mathcad software.Conclusion. Taking into account the stiffness in the structures of the elements in the industrial building frameworks reduces metal consumption.

Disain Kebutuhan Tulangan Glass Fiber Reinforced Polymer (GFRP) Untuk Elemen Struktur Pada Bangunan Beton Bertulang

Fiber Reinforced Polymer is a combination of two main materials Resin Polymer (plastic) as a binder matrix and Fiber (fiber) as reinforcement. This material has three fibers, namely Carbon, Glass, and Aramid. Glass fiber was used in this study, because it has a greater strain compared to other fibers. This study aims to design reinforced concrete structures using steel reinforcement and GFRP as well as to compare the reinforcement requirements of each reinforced concrete. Calculation of reinforcement for steel reinforced concrete refers to SNI 1726-2019, while for GFRP reinforced concrete it is based on ACI 440 1R-2015. This research begins by collecting data in the form of a design structure drawing of a 6-storey hypothetical building, with a total building height of 23 m. The hypothesis building has the number of spans in the X-axis direction is 5 with a distance between columns of 6 m, while the number of spans in the Y direction is 3 with a distance between columns of 5 m. The column dimensions for all floors are 60 cm x 60 cm, while the beam dimensions are 40 cm x 40 cm. The thickness of the floor and roof slabs is 12 cm and the concrete quality is 30 MPa. For the calculation of structural loading, dead load, live load and earthquake load are used and the design of reinforcement for conventional steel reinforced concrete structures and GFRP is carried out. Steel reinforced concrete structures with GFRP reinforced concrete have differences in the amount and diameter of reinforcement required. For beam elements bearing steel reinforcement, 24 pieces of flexural reinforcement are needed with a diameter of 19 mm, while for beam elements, GFRP reinforcement requires 12 pieces of flexural reinforcement with a diameter of 1 inch to 1,128 inches. For the field area, steel reinforcement beam elements need 12 pieces with a diameter of 19 mm, while for GFRP reinforcing beam elements require 8 pieces of flexural reinforcement with a diameter of 0.875 inch to 1.128 inch. In column elements, steel reinforcement and GFRP reinforcement require the same amount of main reinforcement, which is 32 pieces. However, in terms of diameter, steel reinforcement requires 25 mm diameter reinforcement, while GFRP is 1 inch in diameter.

A comparison of latent semantic analysis and correspondence analysis of document-term matrices

Abstract Latent semantic analysis (LSA) and correspondence analysis (CA) are two techniques that use a singular value decomposition for dimensionality reduction. LSA has been extensively used to obtain low-dimensional representations that capture relationships among documents and terms. In this article, we present a theoretical analysis and comparison of the two techniques in the context of document-term matrices. We show that CA has some attractive properties as compared to LSA, for instance that effects of margins, that is, sums of row elements and column elements, arising from differing document lengths and term frequencies are effectively eliminated so that the CA solution is optimally suited to focus on relationships among documents and terms. A unifying framework is proposed that includes both CA and LSA as special cases. We empirically compare CA to various LSA-based methods on text categorization in English and authorship attribution on historical Dutch texts and find that CA performs significantly better. We also apply CA to a long-standing question regarding the authorship of the Dutch national anthem Wilhelmus and provide further support that it can be attributed to the author Datheen, among several contenders.

Damage Analysis of Reinforced Concrete Columns Based on Fiber Beam–Column Element

The method of damage analysis of reinforced concrete columns based on the fiber element model is established by combining the uniaxial damage constitutive model of concrete and steel with the fiber beam–column element model. The quasi-static test and the shaking table test of reinforced concrete columns are simulated and analyzed, respectively. The results show that the established fiber element model can predict nonlinear mechanical behavior and the damage distribution of reinforced concrete columns with good accuracy. Furthermore, the model can effectively simulate the evolution process of damage of columns, and describe weak parts of columns, and has high computational efficiency and solution accuracy, thus providing a practical analysis method for the simulation of building structures during earthquake.

Ductility and Distribution of Strains on Column Reinforcement Retrofit with Wire Mesh

Abstract A lot of damage to building structures due to earthquakes is damage to column components that serve as vertical elements to pass the load to the foundation. Ductility is one of the parameters that must be owned by the column and as part of the column, longitudinal reinforcement is part of the column element that is quite vital and one of the parameters that can be studied is the distribution of strains that occur in longitudinal reinforcement when burdened with cyclic loads. In this study, a study of the ductility and distribution of strain values occurred in the reinforcement of control columns and retrofit columns with wire mesh size M6. From the test results in can be that on the column that is retrofit with wire mesh and SCC experienced an increase in the value of ductility. While the strain value on the reinforcement of the control column and retrofit column tends to enlarge when it is in the plastic hinge area of the column. In the control column the strain value that occurs in the plastic hinge area is greater than the strain value in the retrofit column, so that in the control column the plastic hinge mechanism has begun to form, while in the retrofit column the plastic hinge mechanism has not been formed due to higher stiffness.

Building Analysis of the Lill Hajj Wall Umrah Building Based on Functionality of the Building for Umrah and Hajj Pilgrims

PT Lill Hajj Wall Umrah is targeted to get 5,226 consumers per year or equivalent to 436 people per month by 2030. The old office in the form of a shophouse with a building area of 119.75 m² for a capacity of 99 people is considered inadequate to serve 436 consumers per month, so PT Lill Hajj Wall Umrah needs a new office with a meeting room of at least 523.2 m². A new office will be planned based on SNI 2847-2019, SNI 1726-2019, SNI 1727-2020, and PBI 1983. The planning results are in the form of an analysis of the new office structure with building dimensions of 28.30 x 23.35m, four floors with a building area of 4,503 m². The material specifications of the building structure are concrete quality (fc') 41.5 MPa, melted reinforcing steel quality (fy) 400 MPa (BJTS), and 280 MPa (BJTP). Basement floor column dimensions 0.6 x 0.6 m, first to fourth floor columns 0.5 x 0.6 m, rooftop columns 0.4 x 0.4 m, main beam dimensions 0.25 x 0.35 m, child beams 0.25x0.5 m, stair beams 0.25 x 0.35 m, roof deck beams 0.25 x 0.3 m and 0.3 x 0.4 m, concrete slab thickness 0.15 m. The results of structural modeling using the Etabs application showed that there was no over-strength (O/S) in the column and beam structure elements. The results of the design of the new office building Lill Hajj Wall Umrah in the form of a basement floor equipped with prayer room facilities covering an area of 14 m2, a generator room covering an area of 15.28 m2, a pump room covering an area of 15.28 m2, parking covering an area of 781.53 m2. The first floor is equipped with VIP room facilities covering an area of 33.33 m2, a prayer room covering an area of 25.87 m2, a toilet covering an area of 44.93 m2, and a boutique room covering an area of 55.22 m2, and a warehouse covering an area of 12.3 m2. The second floor is equipped with a meeting room covering an area of 47.9 m2, a manager's room covering an area of 36.7 m2, a toilet covering an area of 30.9 m2, a prayer room covering an area of 16.08 m2, a boardroom covering an area of 80.59 m2 and a waiting room covering an area of 45 m2. The third and fourth floors are equipped with toilets covering an area of 25.75 m2, a prayer room covering an area of 23.95 m2, and a ballroom of 383.75 m2. The estimated budget for the construction of lill Hajj Wall Umrah's new office is Rp 7.612.645.721.- and takes 406 working days for construction.

Modeling of cyclically loaded square thin-walled CSFT columns stiffened by diagonal ribs using OpenSees

Among various proposed stiffening forms, the diagonal binding ribs, made of thin-walled steel plates with circular holes and welded to the steel tube, were found to particularly effective in improve the cyclic-bending and cyclic-shear behavior of square thin-walled concrete-filled steel tubular (CFST) columns. Although the mechanical behavior can be obtained from the experiments, numerical models are still needed to expand the range of investigation beyond what was tested physically and to facilitate the practical design. A 3D model using shell and solid elements is able to explicitly show the influence of different parameters, and simulate the details including the holes in diagonal ribs and the contact interaction between different parts. However, such analyses are relatively complicated, time-consuming, and are susceptible to numerical issues that cause lack of convergence. By contrast, a 2D model using fiber-based beam–column elements is far more efficient thus allowing for a wider range of investigation. In this work, the fiber models of flexure-dominated diagonal ribs stiffened square thin-walled concrete-filled steel tubular (DSCFST) columns were firstly developed in OpenSees and validated based on the effective stress–strain relationships of steel tubes and moment–rotation curves of RC bases. The fiber models of shear-dominated DSCFST columns were further developed by defining the nonlinear shear force–deformation relationships at the section level. These models were verified by the test results, and then the effect of the deformable RC base, tube local buckling, shear effect, and types of beam–column elements was analyzed in detail. Based on extensive parametric analyses, the effective stress–strain relationships applicable to various square thin-walled steel tubes stiffened by diagonal ribs and infilled concrete were derived, and the simplified shear force–deformation relationships were proposed. These results facilitate understanding of the behavior of DSCFST columns and lay a foundation for further system-level analysis.

Shear stiffness of sand-fines binary mixtures: Effects of sand gradation and fines content

In this study, a comprehensive experimental programme was carried out on five clean sands of different gradations mixed with low plastic fines using an apparatus that incorporates both resonant column (RC) and bender element (BE) functions. The sand gradation is characterized by uniformity coefficient of host sand (Cus) and grain size ratio (Rd), which is defined as the ratio of the mean grain size of sand to that of fines. The effects of fines content (FC) and sand gradation on small strain shear modulus G0 are analyzed from the experimental results. Both RC and BE test results show that G0 continuously decreases in a non-linear manner as FC increases to 30% and becomes as low as nearly 50% of that of clean sand at the highest FC. The reduction rates with respect to FC are similar regardless of the testing type and the stress dependence of G0 is insensitive to FC. Meanwhile, G0 decreases as Cus or Rd increases at a given FC and void ratio or at a fixed equivalent skeleton void ratio e*. A new predictive model in terms of e* is proposed to evaluate the G0 of sand-fines mixtures to account for the effects of void ratio, confining pressure, FC, and sand gradation within ±20% deviation. Moreover, the rate of shear modulus degradation with shear strain and the damping ratio are higher for sand-fines mixtures with higher FCs.

Mechanical properties of BFRP-reinforced glued laminated wood hollow round column under eccentric pressure

The FRP-wood column elements are lightweight and high performance, meeting the social demand for sustainable construction. In this study, a basalt fiber reinforced polymer (BFRP) reinforced glued laminated wood hollow round column structure is proposed. Small eccentricity compressive tests and numerical simulations were carried out on glued wood hollow columns strengthened with BFRP to study the effect of BFRP arrangement on the mechanical properties of glued wood hollow columns with constant material, size and eccentricity. All samples are compression side of the wood first yielded, and then some samples tensile side of the end of the wood fracture or the central section of the wood was pulled off, which belongs to the typical compression bending failure and conforms to the characteristics of small eccentric compression. The compressive load capacity of the wood column after BFRP pasting was increased by 3.4%∼30.54%, and the lateral flexural stiffness was increased by 1.44%∼23.86%. Meanwhile, pasting BFRP at the end and middle of the wood column can effectively restrain the compression deformation at the end and bending deformation at the middle, and obtain higher load capacity and lateral flexural stiffness. The numerical simulation results agree well with the experimental results and can effectively characterize the mechanical properties of BFRP-reinforced glued laminated wood hollow round column under eccentric loading conditions.

More accurate design equations for cold-formed steel members subjected to combined axial compressive load and bending

Cold-formed steel (CFS) load-bearing members in multi-storey frame systems are subjected to combined actions sourced from gravity and lateral loads. However, limited information is available on the complex interaction behaviour of such elements affected by different buckling modes. This study aims to provide a better understanding of the behaviour and design of CFS sections under various combinations of compression and bending about both major- and minor-axes. Experimentally validated finite element (FE) models of CFS elements were developed in ABAQUS software, accounting for material nonlinearity and geometric imperfections. The validated models were then used to conduct a parametric study to assess the structural performance and failure modes of over 500 CFS elements with various lengths, thicknesses and cross-sectional dimensions under 19 different load eccentricities. It was demonstrated that the element and web slenderness ratios and the magnitude and direction of eccentricity are the key factors affecting the behaviour of the CFS beam–column elements. The accuracy of current design specifications, including American Iron and Steel Institute (AISI-S100), Australian/New Zealand Standard (AS/NZS-4600) and European standard (Eurocode-3) was then investigated. Subsequently, the results were used to propose a new design interaction equation as a function of element and web slenderness ratios. It was shown that the proposed equation could considerably improve the accuracy of the code strength predictions, especially in the case of medium to high slenderness elements. Finally, a reliability analysis was conducted within the framework of the AISI-S100 to ensure that the proposed design equation provides the required level of safety.

Simulation of Cold-Formed Steel Shear Wall Sheathed with Steel Plate: Non-Linear Finite Element Modelling and Analysis

The usage of cold-formed steel (CFS) is gaining popularity all around the world these days. Buildings made of such elements as an independent structural system are applied in the construction of small commercial complexes, low-raised buildings, industrial units, and single-story sports halls. CFS shear walls sheathed with steel sheets are the most popular lateral-load resisting system in low to mid-raised structures. In this paper, a full-scale steel seated CFS shear wall has been simulated by a non-linear finite element method. Furthermore, parametric studies have been carried out to analyze the effects of the blocking members, fastener spacing at steel plate to boundary frame connections, and steel sheet thickness on the behavior of CFS shear wall sheathed with steel plate. It was concluded that the blocking members prevent the studs from twisting and decrease the local bucking of the studs. Meanwhile, the results indicate that the thickness of the steel plate affects the shear strength of the CFS shear wall system to an extent. Besides, increasing the spacing of the fasteners at the connection of the steel plate to the frame system affects the buckling mode of the steel plate, and by increasing the spacing of the fasteners from 100 mm to 150 mm and 200 mm the nominal shear strength of the wall system decreased by 6.5% and 14.1% respectively, while decreasing the fastener spacing causes web distortion of the boundary column elements.

RICT: Rotating image computed tomography with a one-to-one reversible image rotation algorithm.

The Mueller, Siddon and Joseph weighting algorithms are frequently used for projection and back-projection, which are relatively complicated when they are implemented in computer code. This study aims to reduce the actual complexity of the projection and back-projection. First, we neglect the exact shape of the pixel, so that its shadow is a rectangle projecting precisely to a detector bin, which implies that all the pixel weights are exactly 1 for each ray through them, otherwise are exactly 0. Next, a one-to-one reversible image rotation algorithm (RIRA) is proposed to compute the projection and back-projection, where two one-to-one mapping lists namely, U and V, are used to store the coordinates of a rotated pixel and its corresponding new coordinates, respectively. For each 2D projection, the projection is simply the column sum in each orientation according to the lists U and V. For each 2D back-projection, it is simply to arrange the projection to the corresponding column element according to the lists U and V. Thus, there is no need for an interpolation in the projection and back-projection. Last, a rotating image computed tomography (RICT) based on RIRA is proposed to reconstruct the image. Experiments show the RICT reconstructs a good image that is close to the result of filtered back-projection (FBP) method according to the RMSE, PSNR and MSSIM values. What's more, our weight, projection and back-projection are much easier to be implemented in computer code than the FBP method. This study demonstrates that the RIRA method has potential to be used to simplify many computed tomography image reconstruction algorithms.

Three-dimensional ultrafast ultrasound imaging of blood flow using row-column addressing array: A simulation study

Three-dimensional (3D) ultrafast imaging is important for ultrasound technology development. The traditional 3D imaging method based on fully sampled two-dimensional (2D) matrix often requires a large number of electronic channels with high density which limits the aperture size and imaging resolution in application. Recently developed row-column addressing (RCA) matrix effectively reduces the number of electronic channels from <i>N</i> × <i>N</i> to <i>N</i> + <i>N</i> by addressing the row and column elements. The beamforming strategy designed for 3D ultrasound imaging was based on the coherent compounding of orthogonal plane waves (OPW). Such a multi-angle OPW compounding strategy achieves virtual transmit focusing in both directions by transmitting a set of plane waves in one direction and receiving along the orthogonal direction, which finally leads to an isotropic point spread function (PSF). In this paper, multi-angle OPW method was investigated for 3D blood flow imaging using an RCA matrix with 128 rows and 128 columns, centered at 6 MHz. The delay and sum (DAS) beamforming was developed for coherent OPW compounding, and the singular value decomposition (SVD) filtering method was used for separating the dynamic blood flow signals from the static tissue signals and low-amplitude noise. The Doppler velocity was computed by the autocorrelation method, and finally the 3D power Doppler and color Doppler imaging of the blood flow were realized. To evaluate the imaging quality and investigate the effect of different OPW tilting angles, quantitative analysis was carried out using multiple parameters, including –6 dB resolution measurements of the PSF, SNR of the power Doppler images and velocity distribution of the color Doppler. The –6 dB resolution is improved from 0.986 mm to 0.493 mm with the number of angles increasing from 5 to 33. With 17 plane wave angles, the SNR of the power Doppler image reaches 30 dB, and the average deviation between the velocity distribution along the diameter of the blood flow phantom and the actual value is about 26.0%. In conclusion, results show that the ultrafast 3D imaging method based on RCA matrix can obtain 3D B-mode, power Doppler and color Doppler images. Increasing the number of tilting angles and enlarging the angle range can significantly improve the imaging quality. The proposed method can be helpful for developing 3D ultrafast ultrasound Doppler imaging and functional ultrasound imaging based on neuro-vascular coupling.

МЕТОД КОДОВОЇ ЛІНІЙНОЇ ІНТЕРПОЛЯЦІЇ ДЛЯ ФОРМУВАННЯ ВІДРІЗКІВ ПРЯМИХ

Graphic images are formed using graphic primitives. These are the smallest, indivisible from the point of view of application programs, graphic elements used as the basis for building more complex images. Among the graphic primitives, the segments of straight lines, for the formation of which provides linear interpolation, have the highest specific weight. The performance of forming a graphic scene depends on the time of vector generation, therefore the question of increasing the performance of linear interpolation is relevant, especially for dynamic images. With the use of matrix screens and matrix executive bodies in registration devices, the possibility of one-stroke reproduction of row or column elements appears, which allows you to significantly increase the speed of these devices. This mode of operation is promising. Its organization requires the development of interpolation methods that allow in one interpolation cycle to receive the increment code in a row or column (code interpolation). A coded linear interpolation method is proposed, the feature of which is determined in each interpolation clock of digital segments, which includes the number of increments of the same type with the same ordinate (abscissa). For this cycle, prepare for interpolation a larger increment of the line segment to a smaller one. In the future, this ratio and the remainder of the division are used to determine digital segments. In the proposed method, the remainder of the division of a larger increment by a smaller one is accumulated, which is equal to the smaller increment. This allows you to eliminate the accumulation of error and ensure that the end point of the straight line segment is reached. The maximum interpolation error in this case does not exceed half of the discretization step, which is due to the symmetry of the error. The code linear interpolation algorithm is proposed. The research carried out in the work can be used to build high-performance computer graphics tools.

Planning of Development Upper Structure of the Rorotan Labor Intensive Flats North Jakarta

The planning for this 16-storey building is a re-planning of the constructionproject for the Padat Karya Flats located in Rorotan, North Jakarta. Thisbuilding planning is carried out based on the procedure for calculatingconcrete structures for buildings (SNI 2847:2019). The data for this buildingplan was obtained from the architect planning the construction of the RorotanSolid Work Flats. The design of the superstructure includes the planning ofslab, beam and column elements; The scope of the discussion includescalculation of loading, calculation of initial dimensions, ETABS analysis,control of analysis results, final dimension design and reinforcement, designdrawings. The material used is reinforced concrete with a concrete quality offc'35 Mpa fc’40 Mpa and fy 420 Mpa. The basics of planning refer to SNI2847:2019 Procedures for Planning Concrete Structures for Buildings. AndSNI 1726:2019 Earthquake Resistance Planning for Building Structures.Structural analysis using ETABS program with dynamic analysis of ResponseSpectrum.The keyword Multi-storey building, planning, superstructure, slab,column, beam.

The Effect of Different Soil Classes on Earthquake Demands of Reinforced Concrete Structures: Case Study for Sakarya

In this study, it is aimed to investigate the effect of different soil classes on the behavior of the structure under earthquake loads. An evaluation was made for five-storey and eight-story reinforced concrete (RC) frame structures considering the three different soil classes (ZC, ZD, ZE) defined in the Turkish Building Earthquake Code 2018 (TBEC 2018) and the current earthquake hazard of Sakarya. In the structural system of the RC frame, the cross-section geometry and reinforcement details of the columns and beams were designed by considering the design criteria in TBEC 2018. While determining the dynamic behavior of the structure, the effective bending rigidity defined for column and beam elements in TBEC 2018 was used. For the RC frame structural model, the base shear force, story displacements and story drifts were investigated comparatively by using the mode superposition method in the SAP2000 finite element analysis program. When the results are compared, it is seen that as the soil stiffness decreases, the force and displacement demands on the structure increase.

Lateral deformation and buckling analysis of piles including shear effects: Numerical analysis

Piles are one-dimensional (1D) beam–column elements used to support tall buildings, onshore and offshore structures, bridges, wind turbines, etc. In practice, piles are commonly designed using the Euler–Bernoulli Theory. However, this theory is only considered appropriate for long, slender piles because it neglects the contribution of the shear deformation on the pile response. The effect of the shear deformation might be of importance in short, rigid and large-diameter piles such as monopiles, and it should be considered in the analysis. In geotechnical engineering, studies addressing this effect and its interaction with the surrounding soil are scarce and very limited. The aim of this work is to conduct a parametric study to investigate the influence of the shear deformation, semi-rigid connections and pile/soil stiffness ratio on the head deflection, head rotation and first-mode of critical load of an embedded pile. For this purpose, the well-known commercial FE software SAP2000 is employed. Four examples are presented to show the effect of the shear deformation on reinforced concrete (RC) and hollow circular piles embedded in either homogeneous or non-homogeneous soil. For lateral deformation analysis, it is found that deflections and rotations at the pile head considerably increase when the shear deformation is taken into account and they are of most significance at low values of pile/soil stiffness ratios. For buckling analysis, Timoshenko’s theory shows that the critical load notably increases as the stiffness of the surrounding soil increases and, regardless of the soil/pile stiffness ratio, it rapidly decreases as the shear stiffness of the pile decreases.

Planning of Development Upper Structure of the Rorotan Labor Intensive Flats North Jakarta

The planning for this 16-storey building is a re-planning of the construction project for the Padat Karya Flats located in Rorotan, North Jakarta. This building planning is carried out based on the procedure for calculating concrete structures for buildings (SNI 2847:2019). The data for this building plan was obtained from the architect planning the construction of the Rorotan Solid Work Flats. The design of the superstructure includes the planning of slab, beam and column elements; The scope of the discussion includes calculation of loading, calculation of initial dimensions, ETABS analysis, control of analysis results, final dimension design and reinforcement, design drawings. The material used is reinforced concrete with a concrete quality of fc'35 Mpa fc’40 Mpa and fy 420 Mpa. The basics of planning refer to SNI 2847:2019 Procedures for Planning Concrete Structures for Buildings. And SNI 1726:2019 Earthquake Resistance Planning for Building Structures. Structural analysis using ETABS program with dynamic analysis of Response Spectrum.The keyword Multi-storey building, planning, superstructure, slab, column, beam.