Q-1: Direct shear tests were performed on a dry, sandy soil. The size of the specimen was 50 mm x 50 mm x 19 mm. Test results are as follows: Test no. Normal force (N) Shear force at failure (N) 1 89 2 133 3 311 4 445 53.4 81.4 187.3 267.3 Determine shear strength parameters