This paper presents our approach and results in the Search and Anchoring in Video Archives task at MediaEval, 2015. The Search part aims at returning a ranked list of video segments that are relevant to a textual user query. The Anchoring part focuses on identifying video segments that would encourage further exploration within the archive. A two step approach is implemented for both sub-tasks. The first step is common to both. This step consists in generating a list of potential anchor segments and response-query segments relying on a hierarchical topical structuring technique; In the second step, for each query, the best 20 segments are selected according to content based comparisons, while for the anchor detection sub-task, the segments are ranked based on a cohesion measure. The use of the hierarchical topical structure helps to propose segments of variable length at different levels of details with precise jump-in points for them. More, the algorithm deriving the structure relies on the burstiness phenomenon in word occurrences which gives an advantage over the classical bag-of-words model.