Recently, Associate professor Sun Jianqiao from the School of Civil Engineering, Tianjin University, returned to Shanghai aboard China’s icebreaker Xuelong 2 (Snow Dragon 2), marking the successful conclusion of his team’s work in the 15th Chinese Arctic Scientific Expedition.

    This expedition was anchored in a Major Program of the National Natural Science Foundation of China (NSFC) entitled The Tran-scale Evolution Law of Sea Ice Mechanical Behavior. Its core objective was to unravel the multi-scale effects that govern sea ice’s mechanical properties—a longstanding focus in polar marine engineering research.

Key Achievements in In-situ Testing

   During the expedition, the team completed a suite of pioneering sea ice mechanical tests, yielding critical first-hand data:

63 sets of in-situ sea ice borehole strength tests

1 set of in-situ sea ice cantilever beam bending strength tests

43 sets of three-point bending strength tests

    Notably, both the in-situ borehole strength test and in-situ cantilever beam bending test represent China’s first successful implementation of such experiments in polar regions—a significant milestone in advancing domestic polar marine engineering research.

Highlights of the 15th Arctic Expedition

   The 15th Arctic Scientific Expedition was China’s largest Arctic expedition to date, involving four ships: Xuelong 2 (icebreaker), Jidi (Polar), Shenhai Yihao (Deep Sea No.1), and Tansuo Sanhao (Exploration No.3). It integrated tasks from two national-level initiatives: the NSFC and China’s National Key R&D Program.

   The expedition’s innovative multi-vessel collaboration in Arctic high-latitude waters delivered three major outcomes:

   Enhanced the ability to conduct synchronous observations across the Arctic;

Filled critical gaps in observational data for high-latitude Arctic regions;

Laid a foundation for improving global marine environment prediction and forecasting systems.

Significance for Polar Research & Strategy

    Understanding sea ice’s mechanical behavior is not just a scientific priority—it is a safety imperative for navigation, oil drilling, and research operations in ice-covered polar waters. However, the “multi-scale effect” of sea ice mechanics (i.e., how properties vary across different size scales) has long been an unresolved challenge in the field.

    To address this, the Tianjin University team conducted in-situ tests for Arctic sea ice spanning three key scales:

Centimeter-scale

Decimeter-scale

Above-meter-scale

    Complementary tests at the millimeter-scale (crystal level) are now underway, using ice samples collected during the expedition. These data and subsequent research findings are expected to:

    Push the frontiers of global sea ice mechanics research;

    Provide technical support for China’s polar strategy, including safe navigation, resource exploration, and climate change research.