Claim Knowledge Graph Construction and GraphRAG-Based Question-Answering System

Traditional claim management relies heavily on manual analysis and expert judgment, resulting in inefficiencies, information omissions, and heightened risks of disputes. To address these challenges, this paper constructs a domain-specific ontology for construction engineering claims through a five-step process, organizing the relevant knowledge into five unified core classes. Based on this ontology, a knowledge graph is built and stored in Neo4j. The resulting knowledge graph-enhanced LLM question-answering system, evaluated using BLEU-4, BERT-Cosine similarity, ROUGE-1, and ROUGE-L metrics, demonstrates superior performance compared to both the base LLM and Vector RAG approaches. The results indicate that the proposed ontology effectively serves the purpose of knowledge sharing and reuse while providing practical support for construction claim management.