Khan Shahzada

Experimental Seismic Performance Evaluation of Unreinforced Brick Masonry Buildings

This paper presents an experimental study on the performance of a full-scale unreinforced brick masonry (URM) building system tested under quasi-static loading at the Earthquake Engineering Centre, University of Engineering and Technology in Peshawar, Pakistan. The configuration and materials used in the single-story URM building are typical of those found in the northern areas of Pakistan affected by the 2005 Kashmir earthquake. This study is a part of ongoing research for the earthquake impact assessment of the city of Abbottabad. Combined shear and flexural behavior was observed during the test. The experimental data was analyzed and is presented in the form of force-deformation hysteresis loops and envelope curves. Based on the measured data, different performance levels have been established. The measured response of the test structure is also compared to the estimated response obtained using three capacity evaluation procedures and the two are found to be in good agreement.

Experimental Behavior of Full Scale URM Building Retrofitted with Ferrocement Overlay

This paper presents a study on the behavior of a damaged full scale unreinforced brick masonry building, retrofitted with ferrocement overlay and cement based grout injection, tested under cyclic loading. Damage mechanism and force-deformation behavior of the retrofitted structure are compared with its pre-damaged response to quantify the beneficial effects of retrofitting scheme. The lateral load capacity of the retrofitted building was significantly improved and the damage mechanism was transformed from mixed compression-flexural-shear mode to a more stable flexural rocking mode. The energy dissipation capacity, however, remained unchanged and the deformation capacity was slightly decreased.

Retrofitting of Full-Scale Confined Masonry Building Using Ferro-Cement Overlay

AbstractIn this paper, the performance of a full-scale single-story confined masonry building was investigated by subjecting it to quasi-static cyclic loading. The configuration and materials used ...

Stream Flow Modeling of River Swat Using Regression and Artificial Neural Networks (ANNs) Techniques

This paper presents the utility of Artificial Neural Networks and Regression analysis for the stream flow modeling in Swat River at five discharge gauge station. As an appropriate intelligent model is identified, Artificial Neural Networks (ANNs) is evaluated by comparing it to regression analysis and the available field data. ANNs namely feed forward back propagation neural network (FFBPNN) and regression analysis are introduced and implemented. The research study successfully compared the performance of the ANN and regression models that validated the utility of the two modeling techniques as effective applications to stream flow forecasting.

Shake Table Test of Confined Brick Masonry Building

This paper presents the shake table test of a one-forth scaled model, representing a typical Pakistani three stories confined brick masonry building. The model was constructed following complete model similitude and subjected to a series of sinusoidal base motions of increasing amplitude at a constant frequency equivalent to the predominant frequency of JMA Kobe-1995 earthquake record. The dynamic test data was processed and analyzed to generate the force-deformation curve, ductility ratio and response modification factor of the system. A shear-dominated failure mode was observed. As expected, the ground storey was found to suffer more damage than the other two stories. Out-of-plane failure of walls and crushing of concrete in confining elements were also noted in the final test runs. Based on the damage mechanism and force-deformation characteristics, various performance levels are suggested.

Earthquake Disaster Mitigation through Retrofitting of Unreinforced Concrete Block Masonry Buildings

This paper presents an experimental study on the improvement of unreinforced block masonry buildings against earthquake disasters. Unreinforced concrete block masonry piers have been tested for lateral strength before and after retrofitting. Welded mesh and injection of cement grout techniques have been used for piers retrofitting. The analysis of experimental results demonstrates that proper retrofitting can decrease the risk to concrete block masonry buildings in future scenario earthquakes. Retrofitting increases not only the overall strength of unreinforced masonry piers but also the ductility.

STABILITY ANALYSIS OF SOIL SLOPE IN SWABI, PAKISTAN

In this study, slope stability analysis for a particular type of soil in Swabi area was carried out using the method of slices. Gravity load and seismic load were considered in the stability analysis. SLOPE/W and SIGMA/W software of Geo studio package were used for analysis under both dry and completely saturated conditions. Pseudo-static approach was used for the seismic stability analysis. The peak ground acceleration value for stability analysis was obtained from the seismic hazard analysis. Two soil slope conditions were considered, and one was found in critical condition. Retaining wall, Soil nails and ground anchors were assumed in the analysis for stability of slope with critical condition. Peak ground acceleration value of 0.235g is determined with site specific deterministic seismic hazard assessment approach. The maximum displacement in the soil slopes with retaining wall, soil nails, and ground anchors are 0.0220, 0.01665 and 0.01529 feet respectively. Results showed that using ground anchors have a factor of safety 1.165 and both the horizontal and vertical deformation values are within the limit. Based on results, ground anchors technique was found to be a suitable method for slope stability in Swabi.

Seismic Resistance of Unreinforced Brick Masonry Buildings: An Experimental Study

This paper presents a study on seismic resistance of typical single and double storey masonry buildings constructed in the southern districts of Pakhthunkhwa, Pakistan. Two types of bricks; wooden and rice husk burnt bricks, have been investigated in combination with mud and cement-sand mortar. Plane and reinforced specimens have been tested in axial compression and diagonal compression. Analysis of the experimental results show that both single and double storey buildings constructed in the study area with mud mortar and mud plaster are seismically vulnerable. However application of the wire mesh on wall surface subsequently plastered increases the strength significantly and make the structure resistant to the earthquake forces.

Improvement of Mechanical Properties and Lateral Resistance of Brick Masonry Walls by Using Indigenous Materials

In this paper, improvement of mechanical properties of unreinforced masonry walls based on the laboratory test results is discussed. Various masonry specimens have been tested by Portable Structural Testing Equipment (PSTE). Masonry prisms have been reinforced with indigenous materials (wire mesh and bamboo) and confined with reinforced concrete elements. The tensile strength, shear strength and lateral resistance of masonry walls increases up to 5.4, 2.73 and 5.65 times respectively by using plaster, wire mesh, bamboo and confinement. The Indigenous materials used in this research work are cheap and easily available as compared to FRP and other materials. Analysis for lateral resistance of masonry walls has been made by using different relationships.