Fire Rating of Post-Installed Anchors and Rebars

Monotonic behaviour of post-installed mechanical anchors installed in prestressed concrete hollow-core floor units

A large proportion of road and railway bridges, present in Turkey served for many years, have been completed their service life or will soon. Continuing safety and sustainability of these bridges under traffic loads have been of great increasing importance to roadway and railway transportation line to be continuous servicing. In addition, the demolition and reconstruction of bridges that have reached the end of their service life or are nearing completion will have a negative impact on the country's economy. All of these requirements' detailed examination of bridges in order to provide economical and safe service, considering current vehicle loads and earthquake loads. The Mahmutçavuş Bridge is investigated as a simply supported continuous composite roadway bridge at this work. The finite-element model of the bridge is constituted by site investigation and measurement. Different truckloads using for the design of the bridge are determined, and static analysis of the bridge is conducted. Seven earthquake records are scaled for two different earthquake design spectrums. The nonlinear time-history analyses are conducted, considering Δ-δ effects. The performance of the bridge for varying truckloads and earthquake loads is investigated, and results are discussed in detail.

Fire Safety Assessment of China's Twelfth National Games Stadiums

Mechanical recycling of plastics from waste from electrical and electronical equipment (WEEE) is increasingly expected by regulators and demanded by original equipment manufacturers (CEMs); however, mechanical recycling is generally recognized to be the most economically costly and technically challenging method of recovering WEEE plastics. With 12% of WEEE plastics requiring the use of flame-retardants in order to ensure appropriate levels of consumer fire safety, there is a distinct need for data from comparative tests on recyclability of various flame-retarded plastics. Ten commercially available flame-retarded plastic grades commonly used in electronic equipment (eight "halogen-free" grades and two grades containing brominated flame-retardants (BFRs)) were subjected to two different recycling scenarios. A standard recycling scenario was carried out by repeatedly extruding the materials and an accelerated hydrolysis scenario was carried out to study the influence of humidity from air during use on the process. Both, virgin and recycled materials were tested for a potential formation of polybrominated dibenzodioxins/furans (PBDD/Fs), their mechanical properties were assessed and the fire safety rating was determined. Results indicate that none of the tested materials showed a potential to form the PBDD/Fs regulated by the German Chemicals Banning Ordinance. The halogen-free plastic grades showed a significant deterioration of mechanical properties after recycling, whereas those plastics containing BFRs were able to pass all test criteria, thus maintaining their original properties. With respect to the fire safety rating, none of the eight tested halogen-free plastic grades could maintain their fire safety rating after five recycling loops, whereas both BFR plastics continued to achieve their fire safety ratings. Therefore the tested BFR containing plastic materials showed superior recycling properties compared to the tested halogen-free plastic grades with respect to all investigated parameters.

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

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.

Construction of the Bagong Dam’s diversion tunnel commenced in 2022. The tunnel, stretching 480 meters in length and measuring 4 meters in dimensions, is positioned directly beneath the dam. Due to the change in the trajectory of the inlet portal, a thorough analysis of the slope stability of the inlet portal is essential. This report presents a comprehensive slope stability analysis using the finite element method (FEM), both with and without earthquake loading. It also includes data for FEM analysis such as subsurface lithology, drill core analysis, observations of the geological strength index (GSI), and pertinent laboratory results. The study area encompasses two main lithologies: moderate weathered calcipulverite limestone and slighly weathered andesite breccia. GSI observations on core drill samples indicate that calcipulverite limestone is poor to fair quality (31-51), and andesite breccia with interbedded claystone is poor to good quality (51-89). The results of the FEM analysis showed that the Critical Strength Reduction Factor (SRF) of the slope decreased after adding earthquake loads. Under static and earthquake loads, the excavated slope at the tunnel inlet with a slope of 45° has a critical SRF value of 4.81 under static load, and 4.62 under seismic load. Based on the calculated SRF value, it can confidently affirm that the condition of the inlet portal slope is safe.

Cyclic test of the columns is of practical relevance to the performance of compression members during an earthquake loading. The strength, ductility and energy absorption capabilities of reinforced concrete (RC) columns subjected to cyclic loading have been estimated by many researchers. These characteristics are not normally inherent in plain concrete but can be achieved by effectively confining columns through transverse reinforcement. An extensive experimental program, in which performance of four RC columns detailed according to provisions of ACI-318-08 was studied in contrast with that of four columns confined by a new proposed technique. This paper presents performance of columns reinforced by standard detailing and cast with 25 and 32 MPa concrete. The experimentally achieved load-displacement hysteresis and backbone curves of two columns are presented. The two approaches which work in conjunction with Response 2000 have been suggested to draw analytical back bone curves of RC columns. The experimental and analytical backbone curves are found in good agreement. This investigation gives a detail insight of the response of RC columns subjected to cyclic loads during their service life. The suggested analytical procedures will be available to the engineers involved in design to appraise the capacity of RC columns.

Stone column reinforced composite foundation of highway under static and seismic load is simulated by numerical method. Fist, calculation model was built up, and verified by in situ test. Then the whole construction process of highway stone column reinforced composite foundation is simulated, after 3 years of traffic load, a seismic load was imposed on bottom of the model. Calculation result show that: in construction and run time period, drainage effect of stone column is significant, when pile length reached to 12m, maximum pore pressure in middle of stone column reduced to about 4 kPa, when pile length reached to 10m, effect of pile length on settlement is small; composite foundation has smaller maximum horizontal displacement in stone column; surface and toe of embankment slope is apt to liquefy under seismic load, stone column can eliminate liquefaction potential to a certain extent, especially in composite foundation range.

The location of the Sidan Spillway Tunnel, as shown on the Earthquake Hazard Zone Map of Bali Island, is in a moderate hazard zone. The support system of the spillway tunnel of the Sidan Dam, Indonesia, was empirically designed based on rock mass classification systems. The objective of this research was to verify the performance of the proposed support system by a numerical method considering the uncertainty in using rock mass classification systems for designing a tunnel support system. In addition, being located in an active seismic region, the seismic load was not considered in the empirical tunnel support design. The proposed tunnel support design was numerically modeled in two dimensions using a finite element method and subjected to a seismic load obtained from probabilistic seismic hazard analysis. A numerical analysis without seismic load was also conducted for comparison. Phase2 software was used for the tunnel stability analysis. The input parameters in the numerical analysis were derived from field investigations (surface engineering geological mapping and evaluation of drilling cores) and laboratory tests. The spillway tunnel area consists of pyroclastic rocks, and the Generalized Hoek-Brown Failure Criterion was selected for the strength parameter of rocks. The suggested support designs are systematic rock bolts (20 mm diameter fully grouted), wired mesh, shotcrete, and steel ribs at specific locations. The numerical models determined that applying the proposed tunnel support system recommended based on the empirical method resulted in a roof strength factor of more than 1.5 under static load & 1.1 under seismic load and roof displacements lower than a 10 cm maximum displacement at every stage of construction. The results verify that the tunnel construction will be stable and fulfill the required safety standard, both under and without seismic loads.

It is more rational to analyze permanent geosynthetic reinforced soil (GRS) walls against seismic loading based on their behavior during service life, but it has seldom been attempted. Calibrated finite-element procedure was used to investigate the reinforcement loads of GRS walls subject to seismic loading during service life, the results of which were compared to those predicted by Federal Highway Administration (FHwA) guideline. Parametric studies were carried out to investigate the effects of various wall parameters and characteristics of earthquake excitations. It is found that due to the isotach behavior of geosynthetics, the reinforcement loads during earthquake that occurs 10 years after construction were similar to those if the earthquake occurs at the end of construction. The FHwA method predicted roughly the maximum reinforcement load but it could not consider strain softening of soil and characteristics of earthquakes. The horizontal locations of maximum reinforcement load in lower reinforceme...

Settlement of combined piled raft foundation of a nuclear power plant in non-liquefiable and liquefiable soils

Objective:The aim of this work is to study the linear behavior of infilled frames with different interface materials like cement mortar, cork and lead under static lateral loading. Method:This paper presents the analytical study of a two bay three storeyed reinforced concrete infilled frame under static lateral loading.A bare frame and infilled frames with various interface materials (cement mortar, cork and lead) have been analysed.Findings:In particular, the paper discusses the lateral stiffness of the frames and gives a comparison on the effect of interface materials on the lateral stiffness of the frames under static lateral load. It is found that cement mortar interface has higher stiffness when compared to lead and cork. Applications/Improvements: The results of this paper can become the basis for further studies on the behaviour of these interface materials under seismic loading.Keywords: Infilled Frames, Interface, Lateral Stiffness and Static Loading

This study evaluates the dimensional parameters (area and depth) of the swimming pool that yields to minimum roof displacement of the Reinforced Concrete (RC) building under seismic loading and also compares the roof displacement of the building considering the water as static dead load and dynamic load (considering sloshing of water). The frame model considered for this study are 10 storied Reinforced Concrete models with swimming pool centrally located at the roof. The area ratio (ratio of the area of the pool to the top floor area of the building) is varied from 0.2 to 0.8 with an increment of 0.1 and the depths of the pool considered are 1.22 m (4 feet), 1.35 m (4.5 feet), and 1.52 m (5 feet). The Linear Time History Analysis (LTHA) of the building is performed considering the three recorded earthquake time histories and eight different sinusoidal loadings. Two different approaches (IS 1893(Part 2): 2014 code method and Yu et al. 1999 Model) are used to represent fluid-structure interaction. The roof displacements are obtained minimum for the case when the area ratio is 0.4 and the depth is 4 feet (1.22 m). Furthermore, the results show that responses are different while considering water as static load and dynamic load.KeywordsSpring mass modelRC buildingArea ratioTime history analysisSwimming poolWater sloshing

One of the major challenges of constructing any high rise building for civil engineers is to make it earthquake resistant. This resistance largely depends on the building's shape and structural system. A comparative study has been done in this paper about the seismic behavior and response of buildings having a regular plan and plan irregularity (re-entrant corners). The 5 building models considered in this study are 15 stories each, the same area and identical weight. Among the 5 building models, 2 are with a regular plan (square, rectangle) and the other 3 building models are with plan irregularity (re-entrant corners). All of them are modeled using ETABS 2015 program for Dhaka, Bangladesh (seismic zone 2). Static loads, wind loads and seismic loads are considered for each model and dynamic response under Bangladesh National Building Code (BNBC) 2006 response spectrum has been meticulously analyzed. A comparison for story displacement, base shear, story drift and time period has been established and explored for dynamic response spectrum among the models. The results show that buildings with irregularity have a greater value of time period, drift and displacement and hereby are more susceptible to damage during an earthquake or disaster.