IQA and GT both very thorough systems for data collection and analysis, and they are quite different from each other, so I personally do not see how you could combine them.
If you try to combine IQA and GT, you complicate your life as a researcher, but not necessarily the quality and efficiency of your research. Clarify your motivation why you want to risk this difficult marriage, then you might find a solution. For the moment I would say to either GT or IQA.
As both David and Charles have said, these are two different methods that can't be and should not be combined. Qualitative research is based on a variety of approaches, each of which comes from different epistemologies. It's important that your methodological design is consistent with its philosophical underpinnings.
If you are trying to determine strategies that people use in HR management and want to create a theory to be tested, you can use either Charmaz or Glaser - but even those spring from different epistemologies and it's important to understand those differences.
On the other hand, if you want to do thematic or affinity analysis and have the participant's voices culminate in a visual representation, then IQA is your better choice.