scholarly journals Analisis Kapasitas Lateral Pada Fondasi Tiang Tunggal Dan Tiang Kelompok Pada Tanah Pasir

2020 ◽  
Vol 3 (4) ◽  
pp. 1105
Author(s):  
Morris Cho ◽  
Hendy Wijaya ◽  
Amelia Yuwono

Fondasi ialah bagian dari suatu sistem rekayasa yang meneruskan beban yang ditopang oleh fondasi dan beratnya sendiri kedalam tanah dan batuan yang terletak dibawahnya. Pada jurnal ini, dilakukan analisa kapasitas lateral tiang tunggal dan tiang kelompok pada tanah pasir. Untuk dapat menganalisis tiang pancang tunggal dan tiang kelompok pada tanah pasir dalam kondisi elastic dapat dilakukan dengan metode analisis statik non linier atau analisis pushover. Analisis pushover adalah prosedur analisis untuk mengetahui keruntuhan suatu bangunan dengan memberikan suatu pola beban statik tertentu dalam arah lateral yang besarnya akan ditingkatkan secara bertahap sampai struktur tersebut mencapai target displacement tertentu atau mencapai pola keruntuhan tertentu. Dari hasil analisis pushover terhadap suatu tiang dihasilkan kurva yang menghubungkan antara base shear dan roof displacement atau disebut kurva kapasitas. Dari kurva kapasitas tersebut dapat dilihat perilaku suatu tiang dari kondisi elastis sampai plastis hingga mengalami kegagalan. Dengan adanya kurva kapasitas yang diperoleh, kita dapat melihat tingkat kinerja suatu tiang berdasarkan metode spektrum kapasitas berdasarkan peraturan ATC-40 dan Pushover Analysis of Underground Structures. The foundation is part of an engineering system that forwards the burden supported by the foundation and its own weight into the soil and rocks beneath. In this journal, an analysis of the lateral capacity of single piles and group piles is carried out on sandy soil. To be able to analyze a single pile and group piles on sandy soil in elastic conditions can be done by non-linear static analysis or pushover analysis. Pushover analysis is an analysis procedure to determine the collapse of a building by providing a certain static load pattern in the lateral direction whose magnitude will be increased gradually until the structure reaches a certain displacement target or reaches a certain collapse pattern. From the results of pushover analysis on a pile, a curve that connects the base shear and roof displacement is called a capacity curve. From the capacity curve, it can be seen the behavior of a pile from elastic to plastic conditions to failure. With the obtained capacity curve, we can see the level of performance of a pile based on the capacity spectrum method based on ATC-40 regulations and Pushover Analysis of Underground Structures.

2016 ◽  
Vol 847 ◽  
pp. 281-289
Author(s):  
Erkan Senol ◽  
Ismail Kose ◽  
Bilge Doran ◽  
Pelin Elif Mezrea ◽  
Bulent Akbas

Adding braces to moment frames is considered to be quite an efficient technique for increasing the global stiffness and strength of the structure. It has not only been used in steel moment frames, but also in reinforced concrete (RC) moment frames in recent years. It certainly can increase the energy absorption capacity of structures and also decrease the demand imposed by seismic ground motions. Steel braces are anchored firmly to boundary beams and columns. They are modeled as truss elements and increase earthquake resistance of the building. Buckling restrained braced frames (BRBFs) in which members yield under both tension and compression without significant buckling have been used in recent years in order to ensure the desired seismic performance of special concentrically braced frames. BRBFs are similar to the special concentrically braced frames in that seismic accelerations are resisted by a building-frame members and diagonal braces whereas the design procedure is different. BRBs should be designed to permit ductile yielding both in compression and tension. In this paper, flat-slab RC building with two different configurations of buckling restraint braces (BRBs) is studied. The buildings have 4-storey with 5 bays in both X-and Y-directions and have been designed according to Turkish Specification of Reinforced Concrete Design (TS 500). In order to explore overall behavior up to failure and lateral load resisting capacities for these buildings, nonlinear static analyses have then been performed using SAP 2000-V14.1. Pushover analysis under constant gravity loads and monotonically increasing lateral forces during an earthquake until a target displacement is reached is generally carried out as an effective tool for performance based design. The major outcome of a pushover analysis is the capacity curve which shows the base shear vs. the roof displacement relationship and represents the overall performance of the building. The results of the analyses are presented in terms of capacity curve and energy dissipation.


2010 ◽  
Vol 163-167 ◽  
pp. 3939-3942
Author(s):  
Zhong Quan Zou ◽  
Li Ping Zhou ◽  
Guo Jing He

Energy-based modal pushover analysis method has been proved to be an appropriate approach to perform seismic analysis for structures whose high mode effect is not negligible. It directly establishes the capacity spectrum based on energy increments, which corrects the deficiency of conventional modal pushover method that the capacity curve would not be unique or even be retorted while the base shear-top displacement curve is established with respect to different reference nodes of the structure. In this paper, a continuous rigid frame bridge with tall piers in seismic zone is analyzed with EMPA method. The results showed that EMPA is more adaptable than conventional methods, and the seismic performance of the bridge can satisfy the demand of the design code.


2017 ◽  
Vol 755 ◽  
pp. 170-180
Author(s):  
Natalino Gattesco ◽  
Ingrid Boem

A method for a simplified modeling of post-and-beam timber buildings braced with nailed shear walls, useful for seismic design purposes, is presented and discussed in the paper. This strategy is based on the schematization of the vertical diaphragms through equivalent diagonal springs with elastic-plastic behavior and allows the assessment of the resisting ground acceleration by performing nonlinear static analysis; the Capacity Spectrum method based on equivalent viscous damping was applied. This nonlinear procedure constitutes a reliable and simple alternative to the linear static analysis using the behavior factor q. The procedures to determine the characteristics of the equivalent elements (stiffness and load-carrying capacity) are based on analytical evaluations, starting from the actual characteristic of shear walls. A comparison between the results of numerical simulation based of more refined and complex models, previously presented by the authors, and this time-reducing, simplified analysis proved the good reliability of the method.


2019 ◽  
Vol 5 (1) ◽  
pp. 85
Author(s):  
Ramdhan Taufik ◽  
Erma Desmaliana ◽  
Amatulhay Pribadi

ABSTRAKKondisi geografis Indonesia memiliki struktur tektonik kompleks. Kondisi ini membuat perencanaan rumah tinggal 2 (dua) lantai membutuhkan pertimbangan khusus dari segi kekuatan dan kekakuan. Penggunaan material kayu sebagai bahan konstruksi di Indonesia masih jarang digunakan. Kayu glulam adalah suatu produk kayu rekayasa yang dibuat dari beberapa bilah kayu yang direkatkan dengan arah sejajar serat menggunakan perekat berupa lem. Penelitian ini bertujuan untuk mengidentifikasi respon struktur pada rumah tinggal menggunakan material kayu glulam dan solid dengan bantuan program ETABS 2016. Berdasarkan analisis yang telah dilakukan, diperoleh nilai periode struktur, gaya geser dasar, dan simpangan antar lantai antara seluruh model menunjukan hasil yang berbeda, perbedaan diakibatkan dari hasil konversi berat jenis dan modulus of elastisity berdasarkan BS EN 1194:1999. Berdasarkan analisis non-linier pushover didapatkan bahwa kayu glulam Nyatoh (kayu kelas III) berada pada level pada kinerja B to IO (Immediate Occupancy), dimana hasil tersebut tidak berbeda jauh dengan kayu solid Bangkirai (kayu kelas I).Kata Kunci: rumah tinggal, kayu glulam, non-linier pushover ABSTRACTGeographical condition of Indonesia has a complex tectonic structure. These conditions create  2-storyhome-planning that require special consideration in terms of strength and rigidity. The use of wood as a construction material in Indonesia is still rarely used. Glulam wood is a wood products engineering made from wooden slats several glued with the direction of the parallel fibers using adhesives. This research aims to identify the structure of the response at home using basic material glulam and solid wood with the help of ETABS 2016 programs. Based on the analysis that has been done, obtained the value of the structure periode, base shear force, and interstory drift between all models show different results, the difference is due to the results of specific gravity conversion and modulus of elasticity base on BS EN 1194:1999. Based on non-linear pushover analysis, it shows that Nyatoh glulam wood (class III wood) was at the level of the B to IO (Immediate Occupancy) performance, where the results were not much different from Bangkirai solid wood (class I wood).Keywords: home livingstructure, glulam wood, non-linear pushover


In multistoreyed RCC framed buildings, critical damages are due to seismic ground excitations, which cause catastrophic failuresat the weaker locations. Buildings with two types of structural irregularities namely diaphragm discontinuity and open ground story are considered. Assessment of seismic vulnerability of these buildings is done by using Nonlinear Static Pushover Analysis (NSPA). Performance Based Seismic Design of masonry infilled RCC buildings with two different shape of openings in the diaphragm is considered here with Design Basis Earthquake(DBE) and Maximum Considered Earthquake(MCE) where by selecting appropriate performance criteria in terms of Inter-story drift ratio(IDR) and Inelastic displacement demand ratio(IDDR) are critically observed. The Equivalent Linearization Procedure of Pushover analysis presented in FEMA 440, which is a modification of Capacity Spectrum Method based on ATC-40 guidelines, is performed in ETABS-2016 to study the performance of R.C.C. buildings with diaphragm discontinuity, designed as per IS-1893-2016.


2019 ◽  
Vol 11 (2) ◽  
pp. 202-215
Author(s):  
Shanmukha Shetty ◽  
Subrahmanya R.M. ◽  
Sushanth Bhandary ◽  
Thushar Shetty

Purpose Columns are structural elements that are predominantly subjected to compressive forces and moments that are to be transferred from the super-structure to the sub-structure. The geometrical shape of a column is a significant factor to be considered. The paper aims to discuss this issue. Design/methodology/approach Pushover analysis is carried out, to study the behavior of RC frames with rectangular and specially shaped columns for the same building layout. Findings Reduction of 27.3 percent in base shear, 67.4 percent in spectral displacement, 66.5 percent reduction in storey displacement, 70.22 percent in storey drift and 0.315 percent reduction in storey shear is observed. Practical implications Special shaped RC columns can effectively enhance the structural behavior of high rise structures under seismic excitation in comparison to those with regular shaped RC columns. Originality/value Applications of special shaped columns in structures have showed a great deal of reduction in displacement and shear forces developed due to seismic activity, for the same area of concrete and steel as in rectangular columns.


2020 ◽  
Vol 23 (8) ◽  
pp. 1702-1714
Author(s):  
Wenxiu Liu ◽  
Eric M Lui

This article presents mathematical modeling and parametric study of a type of magnetic negative stiffness dampers. A magnetic negative stiffness damper uses the interaction forces and movement of magnets inside a conductive pipe to achieve inverse force–deformation response and create frequency dependent damping. One advantage of magnetic negative stiffness dampers over other conventional dampers is that they do not add stiffness to the system and hence will not increase the force in the structural members to which the magnetic negative stiffness damper is attached. Using nonlinear regression analysis, simple formulas to describe the magnetic force and electromagnetic damping of a specific type of magnetic negative stiffness dampers are derived. A parametric study is then performed to show that maximum negative stiffness is obtained when the height-to-diameter (aspect) ratio of the magnets is in the range of 0.3–0.4, and for design applications upper bound values for the clear spacing-to-radius ratio and aspect ratio of the magnets are determined to be 3 and 2, respectively. The highest value of damping coefficient is found to correspond to a magnet aspect ratio of 1.6, and for design purpose the pipe wall thickness should be set equal to the height of the magnet. Based on a pushover analysis of three frames modeled as single-degree-of-freedom systems, it is found that the frame with the magnetic negative stiffness damper experiences lower base shear at the expense of a slightly higher residual drift. The effect of base shear reduction is more pronounced when the target displacement is small.


2019 ◽  
Vol 10 (2) ◽  
pp. 18-31
Author(s):  
Radhikesh Prasad Nanda ◽  
Subhrasmita Majumder

In the present article, the performance of base-isolated infilled frames is studied analytically. The seismic performances of four RC buildings, namely RC bare frame without isolator, RC bare frame with isolator, RC infilled frame without isolator, and RC infilled frame with isolator are analysed. The results show a decrease in base shear value and increase in time period due to base isolated buildings, while these parameters are reversely affected due to infills. The decrease in story drift for the base isolated buildings is in phase while considering infill. Also, it can be inferred that plastic hinge formation is greatly affected by the introduction of masonry infill. Hence, relying on base isolation without considering infills may underestimate the seismic performance.


2014 ◽  
Vol 580-583 ◽  
pp. 1449-1457
Author(s):  
Wen Xia Yang ◽  
Qiang Gu ◽  
Ping Zhou Cao ◽  
Rong Jin Shi

In current seismic design procedure, structure base shear is calculated according to the linear elastic response spectra divided by the response modification factor, which accounts for ductility and overstrength of a structural system. In this paper, the response modification factors of Y-eccentric braced steel frames (YECBF) designed based on Chinese Code were evaluated by an improved pushover analysis on 12 examples with various stories and spans lengths. According to the analysis results, the effects of fundamental periods, storey numbers, and spans of frames on the behavior factor were studied. In the end, an appropriate response modification factor was proposed for YECBF designed base on Chinese Code.


2014 ◽  
Vol 57 (2) ◽  
pp. 423-437 ◽  
Author(s):  
JingBo Liu ◽  
WenHui Wang ◽  
Gautam Dasgupta

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