Hydro-mechanical damage processes occur in numerous geological hazards and engineering applications. Despite considerable effort made in the past years, reliable numerical prediction of failure processes in multiphase porous media remains challenging. This is mainly due to the complexity of the involved multi-physical phenomena, as well as the ineffectiveness of conventional mesh-based methods (e.g., FEM) which suffer from large deformation-induced mesh distortion issues and exhibit non-convergent solutions for damage and fracture problems. The objective of this work is to develop a robust meshfree computational framework for effective modeling of hydro-mechanical damage processes. To this end, a fluid pressure projection method is employed in conjunction with the stabilized conforming nodal integration to achieve a stable reproducing kernel mixed formulation for poromechanics. Moreover, a damage particle method is developed for fracture modeling, where a smeared description of cracks is adopted to circumvent the burden associated with modeling complex crack patterns. To eliminate the pathological discretization size sensitivity, a scaling law is introduced in the damage model to ensure that the bulk damage energy dissipation over the nodal representative volume is consistent with the surface fracture energy of the crack segment. In addition, the smeared strain is computed as the boundary integral of displacements in each nodal representative domain, which avoids the ambiguity of taking direct derivatives of non-smooth displacements in the cracking region. As such, the computation of field and state variables along with the regularization procedure are all performed at nodal points, without any interpolation commonly needed in FEM. By incorporating the hydro-mechanical coupling, the damage particle method is capable of capturing the growth of fluid-driven cracks without tedious treatments of moving discontinuities. The effectiveness of the developed meshfree formulation is demonstrated in the modeling of hydraulic fracturing and landslides, which involves extreme deformation phenomena and interactions between solid, water and air phases.