Gokhan Tunc

Cyclic response of "shear" connections between steel outrigger beams and reinforced concrete core walls is presented in this paper. The connections investigated in this paper consisted of a shear tab welded onto a plate that was connected to the core walls through multiple headed studs. The experimental data from six specimens point to a capacity larger than the design value. However, the mode of failure was through pullout of the embedded plate, or fracture of the weld between the studs and plate. Such brittle modes of failure need to be avoided through proper design. A capacity design method based on dissipating the input energy through yielding and fracture of the shear tab was developed. This approach requires a good understanding of the expected capacity of headed studs under combined gravity shear and cyclic axial load (tension and compression). A model was developed and verified against test results from six specimens. A specimen designed based on the proposed design methodology performed very well, and the connection did not fail until shear tab fractured after extensive yielding. The proposed design method is recommended for design of outrigger beam-wall connections.

Turkiye insaat sektorunde “Tuketici” bilinci, ozellikle deprem sirasi ve sonrasinda yapilmasi gerekenlereodaklanmistir. Deprem oncesinde yapilmasi gerekenler konu ile ilgili teknik personelin gorev kapsaminadahil edilmis ve Tuketici’nin bu konudaki bilinclenmesi ise yuzeysel duzeyde birakilarak neredeysetamamen goz ardi edilmistir. Bu yazida, daha bilincli bir tuketici kitlesinin nasil yaratilacagi, depremedayanikli bina kavraminin ihtiyac duyulan yeni yapilanmalarla nasil iyilestirilecegi ve guven kavramininnasil tesis edilecegi hususlarina ait gorus ve onerilerde bulunulmustur. Bu oneriler dogrultusunda insaatcarkinin yeniden saglikli olarak donmesi icin ileriye donuk hedefler belirlenmis ve bu hedeflere nasilulasilacagina dair atilmasi gereken adimlardan bahsedilmistir.

This article discusses public policy as it has beenadapted to the Turkish construction sector. The problemsrelated to current policy are discussed along with theirremedies. The power struggle that exists among the entitiesrepresenting the government and the private sector areinvestigated. The lack of trust that exists in the constructionsector is also evaluated as a key roadblock to qualitymanagement. In the recommendations section, solutions tosuch problems are proposed. Overall, the intent of thisarticle is to elevate the quality of Turkey’s constructionsector by eliminating and/or rehabilitating existing publicpolicy.

The objective of this research was to better understand cyclic response of outrigger beam-core wall connections. The goal was also to overcome some of the deficiencies of past research that did not simulate proper loading and representative reinforcement around the connection region. A unique feature of this study is simultaneous loading of two outrigger beams in conjunction with loading of rectangular or T-shaped cantilevel walls so that the concrete surrounding the connection undergoes realistic deformations and loading.

The objective of this research was to better understand cyclic response of outrigger beam-core wall connections. The goal was also to overcome some of the deficiencies of past research that did not simulate proper loading and representative reinforcement around the connection region. A unique feature of this study is simultaneous loading of two outrigger beams in conjunction with loading of rectangular or T-shaped cantilevel walls so that the concrete surrounding the connection undergoes realistic deformations and loading.

This study assesses the seismic performance of steel-reinforced concrete (SRC) composite columns connected to reinforced concrete (RC) beam joints, and their ability to dissipate seismic energy through inelastic deformations. In this article, experimental aspects regarding the seismic performance of high-ductility and low-ductility steel–concrete composite frame were investigated. The principle design parameter in this study was ductility, which is considered a conceptual framework in Efficiency-Based Seismic Engineering. Thus, attention was focused on assuring various ductility ranges of joints obtained through a detailed study of the Turkish Earthquake Code (TEC 18) [Ministry of Public Works and Housing.: Turkiye Bina Deprem Yonetmeligi (Turkey’s Earthquake Code for Buildings). Official Gazette (2018) (in Turkish).]. After identifying deficiencies and the energy dissipation capacity in the newly proposed joints, two half-scaled frames with specific ductility-related designs were constructed, instrumented, tested, and analyzed. The specimens were tested under displacement-controlled lateral cyclic loading that incorporated constant axial loading to create cyclic tension and compression facets across the joint areas. The test results proved that the SRC column-RC beam frames employing an extra column reinforcement ratio exhibit slightly better seismic performance. Due to the presence of structural steel, the shear failure of the joint was effectively prevented, even after the formation of the plastic hinge on the interface of the beam. During the testing, the column rebars, to some extent, made a minor contribution to the joint strength of the specimen compared to the structural steel that absorbed almost all of the load applied to the frame.

On 27 December 1939, a 7.8 magnitude earthquake struck Erzincan, Turkey, claiming close to 33 000 lives, and leaving 100 000 injured and 250 000 homeless. World War II was in its initial stages, and the USA was particularly concerned about the vulnerable situation in Turkey, since there was a possibility that it would join forces with Germany, as the Ottoman Empire had done in World War I. Consequently, the Turkish request for information on ‘a type of quake resistant concrete construction understood to have been developed in California’, resulted in a flurry of correspondence between numerous Turkish and American actors, including the US State Department, which supplied this material with notable attentiveness. As this article will argue, this request not only represents an early critical juncture in the transfer of earthquake engineering knowledge from the USA to Turkey, but also illustrates how diplomacy and engineering can intersect at pivotal points in time. Engineers and other...

For the first half of the twentieth century, Thompson-Starrett and Co., a New York-based American engineering, construction, and contracting firm, dominated the building scene. In operation between 1899 and 1968, it was a leader in skyscraper construction and large-scale projects, and literally built the New York skyline. It designed and constructed the tallest skyscraper of the era, the Woolworth Building, as well as other iconic Manhattan structures such as the Equitable Building, the American Stock Exchange, the New York Municipal Building, and the Claridge, Algonquin, Roosevelt, St. Regis, and Waldorf-Astoria Hotels. A formidable pioneering force in structural engineering a hundred years ago, Thompson-Starrett is, by and large, forgotten today, especially its post-World War II ventures in Turkey, such as the Sarıyar Dam and the Çeşme Beach Houses, a luxury beachfront cooperative located in Ilıca, Izmir. However, what would prompt the engineering firm responsible for the Woolworth Building to take on the road and utility construction and project management of a Turkish summer resort? The answer lies in Cold War geopolitics and booming private enterprise, both of which, in the 1950s, converged in Turkey, relied on American engineering, and involved a complex process of Americanization.

Push-out tests are used to determine shear connectors’ properties where two small reinforced concrete walls are attached to the top and bottom flanges of an I-section through four shear studs located on both its flanges. In this study, the structural behavior of shear connectors was examined by testing a total of 36 push-out specimens. In these specimens, various test parameters were used. The types of shear connectors and their strengths, their connection types, and the strength of the concrete in which they were embedded were all investigated. Headed, L-shaped, and C-shaped studs were selected in this experimental study to represent different types of shear connectors. These shear connectors were assumed to be either ordinary or high strength steel-embedded in three different types of concrete: ordinary, high strength, and reactive powder concretes. In these tests, the shear connectors were connected through welding or epoxy bonding. The objective of this study was to investigate ...

perimeter frame is designed for gravity loads. The outrigger beams spanning between the central cores and perimeter frame are generally designed and detailed as beams with "shear connections". A typical shear connection is shown in Figure 1. A steel plate with multiple shear studs is embedded in the core wall during casting, which may involve slip-forming. After casting beyond the plate, the web of the steel beam is bolted to a shear tab The focus of this paper is on cyclic response of "shear" connections between steel outrigger beams and reinforced concrete core walls. The experimental program was conducted in two phases. The paper summarizes the first phase during which seven specimens with a number of variables were tested. The connections involved a beam bolted to a shear tab that was welded onto a plate embedded inside the wall. Multiple anchors were used to connect the stud plate to the wall. Test results show that the actual capacity is larger than the design values; however, the mode of failure was brittle (either through pull-out of the embedded plate or by weld fracture at the stud-plate interface) which has to be avoided. A model was developed for accurate prediction of the capacity, and was verified based on the experimental data. This model was used in a capacity design approach in order to dissipate energy in a ductile manner through yielding of the shear tab. The second phase of the research was intended to further examine the cyclic behavior of outrigger beam-wall connections under more realistic loading and boundary conditions. Preliminary observations from this phase are also summarized herein.

Abstract An overview of a number of issues related to design of hybrid structures with reinforced concrete central core walls and perimeter steel frames is presented. Various design options for steel or steel–concrete composite coupling beams and their ...

... To compensate for the unintended unsymmetrical response of the wall in the second specimen, additional longitudinal bars were added to the extreme edge of ... “Displacement-based design of RC structural walls ... Mechanism for transfer of load into outrigger beam and diaphragm. ...

A key factor behind successful performance of outrigger beam–core wall connections in hybrid structures is the adequacy of headed studs that are typically used to connect a stud plate, onto which the outrigger beam is connected through a shear tab, to the wall. In an effort to better understand cyclic behavior of stud groups under combined action of gravity shear and cyclic diaphragm forces, the research reported was undertaken. Six 1/3-scale subassemblies that involve a portion of the wall, connection, and outrigger beam were fabricated and tested. The test results suggest that a design method which closely follows available equations for computing stud capacity results in connections that reach the design loads; however, the mode of failure is stud pullout. This mode of failure does not have any ductility and lacks energy dissipation capabilities. Moreover, the available design equations fail to capture the substantial increase in strength due to wall boundary element reinforcement around the studs. The...