PSI - Issue 47

Nurul Najiha Imam Robit et al. / Procedia Structural Integrity 47 (2023) 597–601 Author name / Structural Integrity Procedia 00 (2019) 000–000

599

3

The ultimate bearing capacity of soil to incorporate the changes of moisture content and degree of saturation under the suction effect for unsaturated and saturated soil conditions adopted Terzaghi’s formula for saturated condition (Yan et al., 2020) and Mohr-Coulomb’s shear strength failure envelope, formulated by Vanapalli and Mohamed in 2007 (Yilmazoglu & Askin Ozocak, 2023) can be analyzed below: (1) Where � and  � are effective cohesion and effective angle of cohesion respectively, S is degree of saturation,  is the fitting parameter, � � � � � � is air entry value, � � � � � ��� is the average matric suction value, � and � are Terzaghi’s bearing capacity factor respectively,  � and  � are Vesic’s shape factor . Methods An educational building of a single two-and-a-half stories was located in UiTM Permatang Pauh, Pulau Pinang at Latitude 5°23'04.7"N and Longitude100°24'46.8"E was selected as a study area. 1.3. Non-Destructive Method for Structural Assessment The point selection was chosen based on the visual inspection that showed evident crack on the building’s surface. These crack assessment properties were obtained for numerical modelling input parameters such as footing strength and stiffness parameters. 1.4. Experimental Method for Geotechnical Assessment Soil samples were collected near the building area. Geotechnical tests, such as moisture content, specific gravity, Atterberg limit, particle size distribution determined the basic properties of soil sample. Unconfined compression test and compaction test were conducted to determine soil strength and compaction characteristics of soil. All tests were performed in accordance with the British Standard 1377. These soil parameters were obtained for numerical modelling input parameters such as soil strength and stiffness parameters.       ' 1 ' c uu tanStan uu    ' S tan N B N  2 a w a w c c b AVE ult q          

Table 1. Soil and foundation properties Properties

Silty sand soil Mohr-Coulomb

Strip footing Linear elastic

Model behavior

Width of footing, B (m) Equivalent thickness, d (m)

2

0.15 12.5

Weight

Unsaturated unit weight,  unsat (kN/m 3 ) Saturated unit weight,  sat (kN/m 3 )

19 21

Young modulus, E (kN/m 2 )

69500

3750 0.15

Poisson ration, 

0.3

Dilatancy angle,  (  )

5

Internal friction angle,  (  )

30.5

Cohesion, c (kN/m 2 )

1