Structural Innovation and Local Agency in Siam: The Hennebique System in Bangkok’s Ananta Samakhom Throne Hall

The adoption of the French Hennebique system in constructing the Ananta Samakhom Throne Hall (1907–1915) introduced advanced reinforced concrete to Siam, but also imposed proprietary constraints, limiting local control over design and contractor selection. Siam’s Public Works Department (PWD) engineers were relegated to supervisory roles under Hennebique’s patent. Meanwhile, Bangkok’s soft soil led to foundation settlement, exposing flaws in the Compressol pile system, employed by Hennebique’s concessionaire. To resolve this, E.G. Gollo, an Italian engineer, employed by the Siamese government, devised a caisson foundation, stabilizing the structure and reducing reliance on Hennebique’s specialists. This article examines how Gollo’s intervention marked a crucial shift in Siam’s modernization, strengthening local agency in architectural development and technological adaptation.