Are 3D-printed houses sturdy? This is the most common question received by Xiaoyan Sun, associate professor from the College of Civil Engineering and Architecture at Zhejiang University.

Theoretical analysis suggested excellent earthquake resistance, but to confirm these findings, Sun and a team of experts from different areas decided to conduct a shaking table test.

Testing earthquake resilience on 3D-printed building model

At a sci-tech park of the Institute of Engineering Mechanics (IEM) under China Earthquake Administration in Sanhe city, Hebei province, China, a team of Chinese experts in intelligent construction, structural engineering, and earthquake resistance conducted an intense “destructive” experiment for a 3D-printed house model.

Researchers mark cracks on the 3D-printed house model at the experiment site. (Source: People’s Daily Online)

Sun had collaborated with Hangzhou Lingtong Technology, which specializes in digital construction and 3D printing design, to precisely calculate the structure's earthquake-proof performance using a 3D digital model.

A state-of-the-art six-degree-of-freedom shaking table is used to simulate earthquakes. To match the dimensions of the shaking table, a scaled-down 3D house model was used for testing, measuring five meters in length and just over one meter in width, which is also the maximum dimensions allowed for testing.

Assessment includes visual inspection and inspection through sensors and devices. The model was equipped with acceleration sensors, displacement sensors, strain gauges, and an advanced optical tracking system empowered by video recognition. Additionally, four ultra-high-speed cameras positioned on either side of the structure could capture the slightest changes during the simulated earthquake.

"These ultra-high-speed cameras can capture 3,000 frames and produce 6GB of image data per second - no structural movement goes unnoticed," explained Liangying Zhu, a staff member with Hefei Zhongke Junda Vision Technology, the manufacturer of the cameras.

A promising result

After a full day of testing, the 3D-printed house model withstood an earthquake with a 6 degree of intensity without any structural damage. When the simulated seismic intensity reached 7 and 8, cracks appeared but did not extend to the structural framework, maintaining overall stability.

Even after an earthquake at a 9 degree of intensity that caused complete cracking, the core structure remained intact without collapse or severe damage. The model successfully passed the test.

Sun explained that 3D-printed concrete buildings bring many advantages. Firstly, they allow for rapid and precise construction through digital design, additive manufacturing, and prefabrication, and can accommodate a range of architectural forms.

Besides that, their hollow-wall design can incorporate reinforced steel frameworks, creating a robust concrete structure with excellent anti-seismic performance and long-term durability.

However, as a novel construction method, 3D-printed concrete houses still require further professional certification and practical testing.