Ancient Chinese Timber Tower Shakes On, Revealing Secrets of Earthquake Survival

For centuries, multi-story wooden towers have risen above the plains of northern China, surviving dynasties, wars, and countless earthquakes without a single steel bolt or concrete footing. How these elegant pavilion-style structures endure violent ground shaking has long fascinated engineers, but rigorous laboratory evidence has been scarce. Now, a team of researchers has put a scaled replica of one of these historic landmarks through a full battery of simulated earthquakes, and the results reveal a structural philosophy that modern seismic designers are only beginning to appreciate: flexibility, not brute strength, is what keeps these towers standing.

The study, published in the Bulletin of Earthquake Engineering, focused on the Guangyue Tower, a traditional hybrid pavilion-style timber structure located in Liaocheng, Shandong Province, in northern China. Led by Xian-Cai Ren of Xi’an University of Architecture and Technology, together with colleagues from Liaocheng University and Qingdao University of Technology, the research team fabricated a 1/4.5-scale model of the tower and mounted it on a shaking table, a laboratory platform capable of reproducing the ground motions of real earthquakes. Three ground motion records of increasing intensity were applied to the model, allowing the researchers to track how the structure’s behavior evolved from mild tremors to rare, severe shaking.

Shaking table tests are among the most demanding experiments in earthquake engineering. The platform must replicate not only the peak acceleration of a seismic event but also its frequency content and duration, all while the instrumented model records accelerations, displacements, and dynamic properties at every level. For heritage timber structures, the challenge is compounded by the need to faithfully reproduce traditional joinery. The Guangyue Tower model incorporated the characteristic features of Chinese pavilion-style construction, including mortise-tenon joints, dou-gong bracket sets, and column feet that rest on stone plinths without rigid anchorage. These connections are deliberately loose by modern standards, and that looseness turned out to be central to the structure’s survival strategy.

Under strong seismic excitation, the model displayed exactly the kind of damage that conservators might fear: significant loosening at the joints and visible cracking in members. Yet the structural consequences were remarkably contained. The fundamental frequency of the model, a measure of its stiffness, dropped by 22.8 percent as the joints worked loose and energy was absorbed through friction and slippage. At the same time, the corresponding damping ratio increased by 59.3 percent, meaning the structure became far more effective at dissipating vibrational energy. In effect, the damage itself acted as a protective mechanism, softening the building and damping its response before deformations could grow dangerous.

Perhaps the most striking finding concerned acceleration. At every story of the model, the acceleration amplification factor, the ratio of the acceleration at that level to the acceleration at the base, remained below 1.0, and the factors decreased as seismic intensity increased. In conventional stiff buildings, accelerations typically amplify toward the roof, imposing large inertial forces on upper levels. The Guangyue Tower model did the opposite: the ground shaking was largely filtered out before it reached the upper stories. This behavior stems from the sliding and rocking of column feet and the energy dissipation at semi-rigid joints, which decouple the superstructure from the most violent components of ground motion.

Deformation capacity proved equally impressive. Under the rarely met earthquake, the most severe shaking level considered, the maximum interstory drift, the relative horizontal displacement between adjacent floors normalized by story height, reached 1/29. For many modern structural systems, drift ratios of this magnitude would raise concerns about collapse or permanent damage. Yet the timber model showed no obvious residual inclination after the shaking stopped. The structure simply returned to its original plumb position, its joints re-seating themselves as the motion subsided. This self-centering behavior, driven by gravity acting on rocking columns and the elastic recovery of timber, is a hallmark of traditional Chinese timber construction and a property that modern engineers often struggle to replicate with rigid connections.

To extend the experimental findings beyond the laboratory, the team developed a simplified numerical model of the structure and validated it against the shaking table measurements. The finite element model reproduced the dynamic responses of the test specimen with good agreement, capturing the frequency shifts, damping changes, and story-level accelerations observed experimentally. With a trustworthy computational surrogate in hand, the researchers could then ask a question that no ethical test program could answer directly: what would happen if the column feet were rigidly fixed to their foundations instead of resting freely on stone plinths?

The numerical comparison delivered a clear verdict. A model with rigid ground-story column foot connections did reduce the maximum interstory drift, making the structure nominally stiffer and less deformable. But this apparent benefit came at a steep price: the roof acceleration response increased significantly, exposing the upper levels of the building to much larger inertial forces. In other words, fixing the columns would trade controlled flexibility for amplified shaking at the top of the tower, potentially overloading roofs, brackets, and upper-story joints. The flexible, sliding column foot, so often dismissed as primitive, is in fact a deliberate seismic fuse that protects the entire building above it.

The implications reach well beyond a single tower in Shandong. Thousands of multi-story traditional timber structures across China, Japan, and Korea face seismic risk, and many have already been damaged in recent events, including the Ms 6.0 Luxian earthquake of 2022, which harmed numerous cultural heritage buildings. Rehabilitation programs guided by modern strengthening instincts, such as anchoring columns or stiffening joints, could inadvertently destroy the very mechanisms that have preserved these buildings for centuries. The study’s authors emphasize that their findings can serve as a reference for the rehabilitation of multi-story traditional hybrid pavilion-style timber structures, and the message for conservation engineers is unambiguous: preserve the flexible behavior of column foot connections if seismic resilience is the goal.

The work also adds to a growing body of experimental evidence on traditional timber engineering, from shaking table studies of Forbidden City palaces and Japanese pagodas to laboratory investigations of dou-gong brackets and mortise-tenon joints. Together, these studies sketch a coherent picture of an ancient building system that achieves earthquake resistance through energy dissipation, joint loosening, rocking, and self-centering rather than through the strength and stiffness that dominate modern codes. As China continues to invest in the protection of its timber heritage, validated numerical models like the one developed in this study offer a practical tool: they allow engineers to test rehabilitation strategies computationally, predict how a real tower will respond to future earthquakes, and ensure that interventions enhance rather than undermine the ingenious flexibility that has kept these wooden giants upright through the centuries.

Subject of Research: Seismic performance of multi-story traditional Chinese pavilion-style timber structures evaluated through shaking table tests and numerical modeling

Article Title: Seismic performance of multi-story traditional hybrid pavilion-style timber structures: shaking table tests and numerical analysis

Article References: Ren, X.-C., Meng, Z.-B., Wang, S.-W., & Cao, Y. (2026). Seismic performance of multi-story traditional hybrid pavilion-style timber structures: shaking table tests and numerical analysis. Bulletin of Earthquake Engineering. https://doi.org/10.1007/s10518-026-02643-1

Image Credits: AI Generated

DOI: 10.1007/s10518-026-02643-1

Keywords: timber structures, seismic performance, shaking table test, Guangyue Tower, mortise-tenon joints, dou-gong brackets, column foot connections, interstory drift, damping ratio, finite element model, heritage conservation, earthquake engineering