Answer: Vertical total load:W=20x30x30x10=180000kN Stress of vertical load=W/A= 180000/(0.3x4x4.7)=31.9MPa Wind induced Mmax=1x30x60x30=54000kNm Earthquake induced Mmax= 5%Wx60x2/3=360000kNm>54000kNm Maximal stress of bending moment= (3/4)x360000/(4.7x4.7x0.3)=+-40.7MPa Maximal stress in pressure is 31.9+40.7=72.6Mpa>40Mpa. The thickness of tube is not enough. 40.7-31.9=8.8 tensile stress,it's not a balance design.Answer: Vertical total load: W=20x30x30x10=180000kN Stress of vertical load=W/A= 180000/(0.3x4x4.7)= 31.9MPa Wind induced Mmax=1x30x60x30=54000kNm Earthquake induced Mmax= 5%Wx60x2/3=360000kNm>54000kNm Maximal stress of bending moment= (3/4)x360000/(4.7x4.7x0.3)=+-40.7MPa Maximal stress in pressure is 31.9+40.7=72.6Mpa>40Mpa. The thickness of tube is not enough. 40.7-31.9=8.8 tensile stress, it’s not a balance design