Sistem dan Model Struktur Iswandi Imran, PhD

Sistem Rangka Penahan Beban Lateral Portal balok-kolom: Elevation

Sistem Dinding Geser (Shear Wall) Deformasi geser umumnya menentukan Shear wall Kolom tepi Elevation Interior gravity frames

Sistem Dinding Geser Konfigurasi shaft elevator Gravity frames Shear walls Hole Coupling beams (balok perangkai)

Sistem Ganda Wall-Frame Dual System: Lateral frames – 25% of lateral load, minimum Hole Shear walls

Flat-Slab and Shear Wall

Core Supported Structure (Jamsostek Bldg)

Tube Building with Widely Spaced Perimeter Columns

Shear Wall-Frame Interaction

Sistem Rangka Penahan Momen A simple MRF - rectangular arrangement of columns and beams - with beams attached to columns with moment resisting connections.

An example of a steel MRF under construction in Oakland, California An example of a steel MRF under construction in Oakland, California. Note that the MRFs are the two frames on the right (observe the deeper columns and beams in the MRFs).

A closer view of an MRF.

An steel building under construction in Taipei, Taiwan An steel building under construction in Taipei, Taiwan. Perimeter frames are moment resisting. Columns are steel box columns.

Tipe SRBK Diagonal Tunggal Bresing V Terbalik Bresing V Bresing X A variety of different bracing arrangements are possible for CBFs. This slide illustrates several common types of CBFs. Bresing X Bresing X 2 Lantai

Inverted V-bracing. Slide courtesy of C.M. Uang

Two story X-bracing. Slide courtesy of C.M. Uang

Two story X-braced frame for bottom stories, with a inverted V-braced frame at the top story. Photo courtesy of Russel Kehl and Wayne Chang, Structural Focus, Gardena, CA

Beberapa Konfigurasi Bresing untuk SRBE There are many possible framing arrangements for EBFs, as illustrated in this slide. The next several slides are photos of actual EBFs. e

An EBF with the links at mid-span of the beams An EBF with the links at mid-span of the beams. This building is located in San Francisco. Note the stiffeners in the link. Note also that the brace connections are not detailed with "fold-lines" as required in SCBFs. The fold-lines are not needed, because braces are not expected to buckle in an EBF.

An example of a single diagonal EBF is a high-rise steel office building located in Taipei, Taiwan. Columns are steel box sections. A close-up of the link region of this frame is shown on the next slide.

The link is attached to the steel box column with a fully welded connection.

An EBF with the links at mid-span of the beams An EBF with the links at mid-span of the beams. This building is located in the San Francisco area. Note the brace to link connections for the wide flange braces. Small segments of the braces were shop welded to the bottom of the beam, with a welded splice provided in the field for connection of the remaining portion of the brace. The adjoining bay to the right is also an EBF, with links attached to the columns.

An EBF with links at mid-span of the beams An EBF with links at mid-span of the beams. This photo was taken during construction of the International Terminal at San Francisco airport.

Another EBF with links at mid-span Another EBF with links at mid-span. This is a control tower at Los Angeles airport.

Diafragma pada Sistem Rangka Penahan Beban Lateral Komponen diafragma (geser): mentransfer beban lateral ke sistem penahan beban lateral Jenis portal penahan lateral Elemen pelat

Diafragma pada Sistem Rangka Penahan Beban Lateral Untuk denah persegi, diafragma umumnya kaku Portal ruang dengan denah persegi Beban lateral terdistribusi sesuai dengan kekakuan portal

Diafragma Kaku versus Diafragma Fleksibel RIGID Center Wall Shear = F/3 FLEX Center Wall Shear = F/2

Persyaratan Diafragma Kaku

PILE CONNECTION The type of connection between the pile and the structure is also important because it determines the kinds of restraint, if any, acting on the pile. Engineers usually assume that one of the following conditions prevails: The free-head condition, means that the top of the pile may freely move laterally and rotate when subjected to shear and/or moment loads. The restrained-head condition (also known as the fixed-head condition), means that the top of the pile may move laterally, but is not pemitted to rotate. Piles connected to a very stiff pile cap closely approximate this condition. The pure moment condition, occurs when there is an applied moment load, but no applied shear load. It results in rotation of the top of the pile, but no lateral movement.

PILE CONNECTION

PILE MODELI NG (a) “fixed” base vs (b) Free base Need for embedment of end bearing piles into the bearing layer

Pile Modeling Modeling the soil-pile system for load-deflection analysis of laterally loaded piles: (a) pile in a soil continuum; (b) model using Winkler springs; (c) deflected pile shape when nonlinear springs described by p-y curves are used to model the soil Model of axial soil pile interaction by discretization of the soil by Winkler springs positioned along the pile shaft.

Representation of Deflected Shape, Bending moments, and Shear Force for Long Pile

FAILURE MODES Failure modes for short piles: (a) rotation for free-head boundary conditions and (b) translation for fixed-head boundary conditions. Failure modes for long piles: (a) formation of one plastic hinge for the free-head boundary condition and (b) formation of two plastic hinges for the fixed-head boundary condition

Penulangan Bored Pile Tidak harus memenuhi persyaratan minimum tulangan kolom (IBC menetapkan tulangan longitudinal minimum 0,25 – 0,5%) Penulangan longitudinal harus memperhatikan momen yang terjadi akibat geser horizontal di kepala tiang Penulangan spiral harus memperhatikan kondisi tahanan lateral tanah. Umumnya, bored pile harus diberi kekangan spiral, seperti kolom, di sepanjang 5xD dari kepala tiang.