GUIYANG, Aug. 22 (Xinhua) -- The Huajiang Grand Canyon Bridge, set to become the world's highest bridge upon completion, began crucial load-bearing tests on Thursday, marking a significant milestone toward its anticipated opening in September.

Once operational, the bridge located in southwest China's Guizhou Province, will be the highest bridge globally -- with a deck soaring 625 meters above the river. The 2,890-meter bridge, which has a span of 1,420 meters, will also become the world's largest span bridge in a mountainous area.

The load tests, expected to last until Sunday, are designed to verify the structural capacity and safety of the bridge, a key part of the Liuzhi to Anlong expressway. A total of 18 trucks, weighing a combined 630 tonnes, were deployed on Thursday. Over the four-day process -- the number of trucks will gradually increase to reach a maximum pressure of 3,300 tonnes.

More than 400 sensors have been installed to monitor deformation and stress in the bridge's main towers, cables and deck under various static and dynamic conditions.

"These tests are the final and most critical exam before the bridge opens to traffic," said Wu Chaoming, project manager of the construction company.

With 92.5 percent of its land made up of mountains and hills, Guizhou has built nearly 30,000 bridges since the late 1970s -- and is now home to almost half of the world's 100 tallest bridges.

The Huajiang Grand Canyon Bridge is expected to greatly enhance regional transportation and boost economic development by improving connectivity in this mountainous region.  ■