The northern Chinese city of Tianjin, as a traditional industrial hub, has made big technological innovations and industrial advancements in recent years.
One of the city's notable achievements is housing China's first large-scale earthquake simulation facility.
In Tianjin University, the national earthquake simulation research facility is pioneering earthquake simulations to test the seismic performance of structures. This groundbreaking research may unveil superior seismic solutions for high-rise buildings and transoceanic bridges in the future.
The facility is as high as a 10-storey building, capable for the testing of large-scale structures.
"The place is 31 meters high, and spans 43 meters. The length of this area is 120 meters. The shake table measures 20 meters by 16 meters, and has a maximum load capacity of 1,350 tons, which is about the weight of more than 20 heavy-duty trucks. The maximum acceleration it can operate is 2.0 gravitational acceleration. Such a large acceleration actually exceeds the intensity of a 9.0-magnitude earthquake," said Liu Mingjie, director of the sci-tech department of the earthquake simulation research facility of Tianjin University.
Using earthquake simulators is the most direct way to study a structure's earthquake-proof ability, offering crucial insights for project design and construction.
The large seismic facility can simulate more than 4,700 recorded seismic activities worldwide, and observe the damage and destruction of structures during earthquakes.
High-accurate sensors are used to record seismic data.
"We have installed more than 500 sensors in total, and the accuracy of these sensors is also very high. For example, the sensor we use to measure structural deformation has a minimum measurement value of 0.1 mm, which is smaller than the diameter of our hair," said Liu.
Each sensor can record data 1,000 times per second, and the data is transmitted to the control room, allowing scientific researchers to understand the displacement and deformation of buildings during earthquakes.
The shake table is supported by hydraulic actuators that provide forces for the simulations.
"This is the place where the hydraulic actuators for the shake table are installed. There are 46 actuators in total. The maximum output of the vertical actuator is 450 tons, and the maximum horizontal output is 250 tons, the accuracy of the actuators can reach 0.1 mm," said Liu.
In the past, due to the limitation of the size of the shake table, structures were scaled down at the same proportion during the seismic performance test.
Now, the current shake table allows models of the same size of the actual structure to go through the seismic test. This generates more accurate data of great scientific research value to study houses' earthquake resistance in earthquake-prone areas.
"What we have here is the only test device in the world that is capable of simultaneous simulation of seismic, waves, and currents with two underwater stations. It can work under a water depth of three meters. We can conduct earthquake simulation research on our offshore super projects such as cross-sea bridges and offshore wind power,"said Liu.
The city has demonstrated technological prowess in dredging technology with the introduction of the cutting-edge dredging vessel "Tiankun."
Built in the Tianjin Shipyard, the dredger features groundbreaking technologies such as a smart articulated cutter and efficient sand pumping system, enabling excavation of seabed rocks and sediments with unprecedented precision and speed.
Equipped with four types cutters made from wear-resistant alloy steel, the vessel can evacuate 6,000 cubic meters of sand per hour and enables versatile operation across various soil types and rock hardness levels. The dredger also has a powerful sand pumping system that can transport sediment up to 15 kilometers away.
Now, it is building a new landmark for the United Arab Emirates (UAE), marking a significant milestone in the country's maritime engineering capabilities.
Since it was put into operation, the state-of-the-art dredging vessel has contributed significantly to the construction of ports, island transformations, and river dredging in countries participating in the Belt and Road Initiative.
North China's Tianjin makes technologic marvels
