Cross Bracing Analysis

Hello,

I have an ordinary frame which has some cross bracings in it. The unit is actually to support small HVAC equipment. I have created a basic model to see if my angles will be able to take that load or not. However, I am designing cross bracings in staad for the first time and instead of designing them as tension only members, I went with releasing My, Mz approach as I want to design them for compression too. Can someone please look at the code and tell me if anything is wrong in it. I am not sure I am getting such less unity ratios. I was expecting less but not to this extent.

Also, the reason to use cross bracings in this frame is to reduce the effective length of angles in both local y and z-direction. Can I just use single diagonal brace with My and Mz releases at the start and end to effectively use the angle capacities and have effective length more then recommended in codes in one direction only?

Thanks

Code - 

STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 17-Apr-19
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 0 16 0; 3 2 0 0; 4 2 16 0; 5 0 0 3; 6 0 16 3; 7 2 0 3; 8 2 16 3;
9 2 15 3; 10 0 15 3; 11 0 15 0; 12 2 15 0; 13 0 8 3; 14 2 8 3; 15 0 8 0;
16 2 8 0;
MEMBER INCIDENCES
1 1 15; 2 3 16; 3 5 13; 4 7 14; 5 2 6; 6 4 8; 7 10 9; 8 9 8; 9 10 6; 10 11 2;
11 12 4; 12 11 12; 13 13 10; 14 14 9; 15 15 11; 16 16 12; 17 13 11; 18 15 12;
19 16 9; 20 14 10; 21 16 11; 22 15 10; 23 13 9; 24 14 12;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 4.176e+006
POISSON 0.3
DENSITY 0.489024
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 5184 FU 8352 RY 1.5 RT 1.2
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
1 TO 24 TABLE ST L35358
CONSTANTS
BETA 45 MEMB 3 5 7 9 13
BETA 135 MEMB 4 8 14
BETA 225 MEMB 2 11 16
BETA 315 MEMB 1 6 10 12 15
MATERIAL STEEL ALL
SUPPORTS
1 3 5 7 PINNED
MEMBER RELEASE
5 TO 7 12 17 TO 24 START MY MZ
5 TO 7 12 17 TO 24 END MY MZ
LOAD 1 LOADTYPE Dead TITLE LOAD CASE 1
MEMBER LOAD
5 6 CON GY -0.15 0.1
5 6 CON GY -0.15 2.8
7 12 CON GY -0.3 1
PERFORM ANALYSIS
PARAMETER 1
CODE AISC UNIFIED 2010
LY 8 MEMB 1 TO 4 8 TO 11 13 TO 16
LZ 8 MEMB 1 TO 4 8 TO 11 13 TO 16
METHOD LRFD
RATIO 0.8 ALL
FU 7200 ALL
FYLD 5184 ALL
CHECK CODE ALL
FINISH