mechanism is the principal transformation process to quench SF in spirals although probably helped by other processes affecting the structure of the galaxies. @BBW13 drew a similar conclusion analysing a sample of 182 disk galaxies in the cluster system Abell901/902. The fraction of galaxies showing asymmetric gas rotation curves, and thus probably affected by RPS [@KKU08], turned out to be 75 per cent higher in the clusters than in the field, the majority of them being morphologically undisturbed. Although these galaxies seemed preferentially located at low clustercentric radii, they also observed a population of dusty and red spirals in the cluster outskirts, which could be also affected by ISM-ICM interactions. The relevance of RPS for quenching SF in cluster galaxies is further complicated by the fact that a non-homogeneous ICM is expected for non virialized merging and post-merging clusters, thus the clustercentric distance is not the only parameter describing the ICM density, i.e. the ram-pressure strength.

The approach of the Shapley Supercluster Survey {#HOW}
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Our study is based on characterizing a dynamically active environment in a multifaceted way and disentangling its effects on galaxy evolution. It has the following main objectives.

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:   To investigate the role of cluster-scale 