I have a 6 ft. retaining wall constructed of a 3 ft cement pony wall topped with a 3ft. landscaping tie wooden wall. The portion that is made of ties is bulging out due to the pressure of the soil pushing against it. I would like to remove the ties and replace it with concrete blocks. The question is: How would I tie the blocks in with the existing 3 ft. cement wall so as to not have the blocks push out from the pressure of the soil? Any suggestions from anyone out there? Thanks.