Modeling and Study of Behavior of Infilled Frames with Different Interface Materials under Static Loading

Infilled frames are generally formed by the composite interaction between the frame and the infilled wall used for functional purposes. The composite interaction increases the in-plane lateral stiffness of the frame, which is considered an advantage. However, the interaction also alters the ductile mode of failure to the brittle mode along with the increased base shear owing to its higher stiffness compared with the bare frame. A detailed and comprehensive study of the literature revealed that many of research works have been done on rectangular and square frames, and studies on trapezoidal infilled frames are scarce. In this article, we studied different configurations of reinforced concrete frame structures known as trapezoidal frames, which have higher stiffness than rectangular frames. A trapezoidal frame is used for industrial buildings, and its behavior under a lateral load has already been established for a bare frame. However, the interaction and behavior of the infilled frame were investigated in this research. The behavior of a trapezoidal single-story frame was examined under both lateral loading and various interface materials. One of the most frequently suggested methods for infilled-frame analysis is the equivalent diagonal strut. Effective strut width design recommendations are available for rectangular and square frames but not for trapezoidal frames for macro modeling. Hence, to make the design easier, an effective diagonal width was developed for different interface materials with respect to the relative stiffness of various frame cross-sections, and further validation was conducted with a framework of ideology from biomimicry using the nature of a one-sixth scale model. The effective strut width for the trapezoidal infilled frame varied between d/8 and d/9 for the cement mortar and cork interfaces, where d is the diagonal length of the frame.

Construction of tall buildings is most common in this twentieth century. Technological development and the modern equipment have reduced the complications in design, analysis and construction of these structures. The seismic damages in these structures are unavoidable unless they are technically designed to be stable or isolated from seismic actions. The energy absorption and energy dissipation in these buildings change based on infill type, openings in infill and interface type used under different loading actions. It is essential to study the combined behaviour of RC main frame and the non-load-carrying structural elements under static and cyclic loading conditions. In this study, an analytical work is carried out using finite element modelling software to understand the performance of multi-storey reinforced concrete (RC) frame, RC frame with infill and infill frame with pneumatic interface pressures (in psi). The structural parameters like load-carrying capacity, maximum displacement, stresses and stiffness under static loading conditions are compared with the RC bare frame.KeywordsRC frameMasonry infillPneumatic interfaceLateral load

This paper aimed to investigate the seismic response of reinforced concrete (RC) frame buildings under linear and non-linear dynamic analysis. Different building models as bare frame and fully masonry infill frame have been developed for performing the analysis. In order to investigate the effect of irregular distributions of masonry infill walls in elevation on the seismic response behavior, an infill frame model with soft story has also been developed. The linear response spectrum (RS) dynamic analysis and the nonlinear time-history (TH) analysis methods are employed. Moreover, the induced energies in terms of input, potential and kinetic are also obtained from the TH analysis. Moreover, the interaction between infill walls and frames leads to considerable change in the induced responses comparable with the bare model.

Designing infilled reinforced concrete frames with the ‘strong frame-weak infill’ principle

Strain investigation of infill frames using FEA package MSC NASTRAN

Analysis of strain around endosseous dental implants opposing natural teeth or implants

Progressive collapse mechanisms of post-tensioned reinforced concrete frames considering effect of infill walls

Numerical analysis of the in-plane behaviour of decoupled masonry infilled RC frames

Pasir Kopo dam will be built to develop infrastructure facilities in Banten province. This dam is supported by a twin diversion tunnel, which is a horseshoe-shaped tunnel with lengths of 413,11 meters and 433,10 meters. As the stability of the natural slope is disturbed by excavation activity for tunneling, slope stability analysis is required to ensure safety during construction and use. The geological engineering in this research was obtained by identifying the core rock sample from BT 01, BTA 01, and BTA 02 by PT. Mettana in 2017-2018 to get information about lithology, level of weathering, and Geological Strength Index (GSI). The index properties test and the mechanical properties are used as material parameters for slope stability. This paper will focus on the slope stability analysis of the diversion tunnel inlet using the limit equilibrium method, namely Bishop’s method and Morgenstern-Price’s method under static and dynamic loads. The research location geomorphology is a hill formed by volcanic eruptions and can be dePined as a rather steep pyroclastic Plow ridge. The diversion tunnel inlet consists of fair-quality lapilli tuff and tuff with moderate weathering. The safety factor using the Bishop simpliPied method is 3,731 under static load and 2,567 under earthquake load. The safety factor using the Morgenstern-Price method is 3,748 under static load and 2,561 under earthquake load. Both methods indicate that the slope stability of the diversion tunnel can be categorized as stable according to the requirements of the Indonesian National Standard (SNI) 8460:2017

In this paper, the in-plane (IP) and out-of-plane (OP) interaction of masonry infill walls with various length-to-height ratios and vertical forces from dead and live loads are studied. For this purpose, calibrated numerical simulation for IP and OP behaviors of infilled frames has been exploited. In this method, first, the vertical loads are applied, then increasing IP displacement is imposed at the top of the models and finally OP demands are applied to the walls up to their failure. Two different methods of applying OP loading are studied: increasing static uniform pressure on the wall, and increasing dynamic acceleration. Three levels of IP displacement demands are considered: at the first reduction of tangential stiffness for IP force-displacement response, at the maximum IP strength, and at the displacement related to 20 % reduction of IP strength. The results obviously show that up to the point of the maximum IP strength capacity, the OP behavior of the considered models slightly enhanced due to the effects of improved arching actions originated from the development of IP compressive diagonal struts. Moreover, slight differences exist between the static and dynamic loadings in OP direction, hence proving the accuracy of the equivalent static loading in determining OP capacity for the studied infilled frames. Comparing the results of masonry infilled frames with those of the corresponding masonry walls indicate that the IP displacements negatively affect the OP strength in the latter, even at small IP displacement demands; however, the rate of OP strength reduction in larger IP drift ratios is lower compared to that of the corresponding infilled frame.

To improve our understanding of the lateral resistance of pile groups, we have performed a series of static and dynamic lateral load tests on a full-scale pile group. The pile group consisted of 0.324 m-diameter steel pipe piles driven closed-ended into cohesive soil with an undrained shear strength of about 45 kPa. The test piles were driven in a 3x5 arrangement at a normalized spacing of 3.92 pile diameters in the direction of loading. A single pile test was also performed for comparison purposes. Lateral resistance was found to be a function of row position with piles in the first row carrying about the same average load as a single pile. The average load decreased for the second and third row piles but then remained about the same for subsequent rows. P-multipliers were determined for each row and were found to decrease as deflection increased. After 15 cycles of loading, the peak static resistance decreased by about 17%. Following static loading, dynamic loads were applied using a statnamic device. The dynamic load-displacement curves were stiffer and had larger hysteretic loops than the static curves. Analyses using an equivalent single degree of freedom model indicate that the damping ratio was between 30 and 40%.

This research presents the results of 14 tests, where the pile is subjected to static lateral loads. The tests are carried out on pile models with different length / diameter ratios embedded in sand with different relative densities. The influence of embedment length to diameter ratios (L/D), relative density and mode of failure of the pile on the ultimate lateral resistance of piles are investigated. A series of different ratios of embedded length to constant diameter ranging from 12 to 30 was used to perform this study. From the results of the experimental models, it is found that, the length to diameter ratio is a significant variable that influences the ultimate resistance of the piles, where lateral static loads were employed to the single pile by a static lateral load using a device designed for this purpose, and due to the static lateral load the pile was deflected. The ultimate lateral resistance of a pile is investigated to specify the behavior of the pile under the effect of lateral loads as a rigid or flexible pile.

Multi-bay and pinned connection steel infilled frames; an experimental and numerical study

A method is presented to analyze and evaluate buried culverts and cut-and-cover tunnels for seismic loading in addition to standard static loading from dead and live loads. With CANDE-2007, a plane–strain finite element program, the soil–structure problem is characterized by a cross-sectional slice through the structure and surrounding soil envelope. First, the static design loads are applied with a series of incremental load steps. Next, the seismic loading condition is simulated by specifying quasi-static displacements at the peripheral boundaries of the soil envelope to produce a shear-racking distortion equivalent to the maximum free-field seismic shear strain from the design earthquake. The proposed method is based on two recently completed NCHRP projects and is presented here in detail. An initial linear-elastic study investigates two basic culvert shapes, circular and rectangular, wherein moment and thrust distributions from CANDE-2007 are shown to compare favorably with closed-form solutions. A second study investigates a nonlinear reinforced concrete box culvert installation under the combination of static and seismic loading. Plots of moment, thrust, and shear distributions show how and where the seismic loading alters the response of static loading, including the effect on safety factors for steel yielding, concrete crushing, and shear failure. It is concluded that the proposed seismic method is rational, easy to apply, and fulfills an engineering need heretofore unfulfilled. The procedure applies to any culvert shape, size, and material, and the safety of the culvert installation may be assessed by working either stress or load and resistance factor design.

A series of static and shake table tests were conducted on pressurized threaded, brazed and mechanical, i.e., grooved pipe joints, commonly used in fire protection systems. The objective of the tests was to understand the behavior and failure modes of these common types of joints under seismic and static lateral loads. The paper presents the measured loads and deflections of the joints up to the point of failure. It also describes the joints’ static and dynamic failure modes. While this information may be limited it can be used to model the joint flexibility under large lateral loads, determine their capacity, and help understand the leak and rupture characteristics of threaded, brazed and clamped joints.