public sealed class TopologyLayer : CompositeLayer, ArcGIS.Desktop.Core.IMetadataInfo, ILayerContainer, IMetadataSource, ITopologyLayerContainer, System.ComponentModel.INotifyPropertyChanged  

var path = @"D:\Data\CommunitySamplesData\Topology\GrandTeton.gdb\BackCountry\Backcountry_Topology";
var lcp = new TopologyLayerCreationParams(new Uri(path));
lcp.Name = "GrandTeton_Backcountry";
lcp.AddAssociatedLayers = true;
var topoLayer = LayerFactory.Instance.CreateLayer<ArcGIS.Desktop.Mapping.TopologyLayer>(lcp, MapView.Active.Map);

//Note: Call within QueuedTask.Run()
//Get the Topology of another Topology layer
var existingTopology = MapView.Active.Map.GetLayersAsFlattenedList().OfType<TopologyLayer>().FirstOrDefault();
if (existingTopology != null)
{
  var topology = existingTopology.GetTopology();
  //Configure the settings for a new Catalog layer using the CatalogDataset of an existing layer
  var topologyLyrParams = new TopologyLayerCreationParams(topology);
  topologyLyrParams.Name = "NewTopologyLayerFromAnotherTopologyLayer";
  topologyLyrParams.AddAssociatedLayers = true;
  LayerFactory.Instance.CreateLayer<TopologyLayer>(topologyLyrParams, MapView.Active.Map);
}