Tropical cyclones (also known as hurricanes or typhoons) are among the most destructive natural disasters globally, causing huge fatalities and economic losses annually. Existing data indicate that global climate change has slowed the translation speed of tropical cyclones, and an inverse relationship exists between translation speed and cyclone-induced rainfall. Furthermore, while the total number of tropical cyclones worldwide shows a declining trend, the frequency of Category 4~5 hurricanes (i.e., super typhoons) has increased overall. The 2017 Atlantic hurricane season caused economic losses of US$125 billion in the United States. In 2025, a hurricane in Texas triggered heavy rainfall, resulting in over 130 fatalities. Hainan Island is located along the core generation and movement path of typhoons, making it one of the regions in China most frequently affected by these storms. In 2014, Super Typhoon Rammasun made landfall in Wenchang, Hainan Province, becoming the strongest typhoon on record to strike China (landfall intensity 70  m·s⁻¹). It caused 24 deaths or missing persons on Hainan Island and direct economic losses of RMB¥11 billion. In 2024, Super Typhoon Yagi, with a landfall intensity second only to that of Super Typhoon Rammasun (62  m·s⁻¹), similarly made landfall in Wenchang, Hainan Province. However, its destructive impact far exceeded that of the Super Typhoon Rammasun, causing 4 deaths and direct economic losses exceeding RMB¥60 billion in Hainan Island.　　Super Typhoon Yagi (international designation: 2411) formed over the ocean east of the Philippines on September 1, 2024, and made landfall along the coast of Wengtian, Wenchang on September 6 (minimum central pressure 915 hPa). It then crossed Haikou and Chengmai before moving into the Qiongzhou Strait and subsequently entering the Beibu Gulf. The area on Hainan Island covered by Force-12-and-above winds was affected for over 9 hours, far exceeding the 3 hours during Super Typhoon Rammasun in 2014. The minimum pressure and maximum wind speed recorded in Wenchang both broke all previous land-based observational records for typhoons in China. From September 4 to 8, Hainan Island experienced widespread heavy to torrential rain, with a maximum accumulated rainfall of 691.2 mm at Jianfeng town, Ledong. Wenchang's precipitation broke its historical daily maximum rainfall record for September. In Haikou, more than 100,000 people were evacuated, about 400 houses collapsed, over 30,000 houses were damaged, the crop-affected area reached 570 km², and direct economic losses exceeded RMB¥26.3 billion. In Wenchang, more than 25,000 houses were damaged, the crop-affected area was about 180 km² (with 110 km² of total crop failure), and economic losses amounted to approximately RMB¥32.7 billion. In recent years, Hainan Province has significantly improved its typhoon defense capabilities by revising engineering construction and equipment-use standards and refining pre-disaster emergency plans, leading to a notable reduction in casualties. However, with continued population and economic growth in coastal areas, the risks posed by super typhoons continue to rise, and the resulting economic losses are becoming increasingly difficult to bear.　　Worldwide, foundational theories and forecasting research on the generation and development of tropical cyclones from a meteorological perspective have been well established, and related findings have played a significant role in reducing tropical cyclone disasters. However, the sporadic occurrence of landfalling super typhoons and their marked regional variability have resulted in relatively limited research on their powerful dynamic impacts on the ground. There is still a lack of sufficient data and experience to systematically reveal their disaster-causing mechanisms, and mature solutions for adaptation and disaster prevention and mitigation strategies have yet to be developed. As a fundamental means for major disaster assessment and scientific research, systematic field investigations are crucial. Following the passage of Super Typhoon Yagi across Hainan Island in 2024, the School of Civil Engineering and Architecture of Hainan University organized an interdisciplinary typhoon disaster investigation team composed of nearly one hundred faculty and students. The team conducted field surveys in the affected areas for over ten days. The survey covered regions within the Force-10-to-17 wind circles of Super Typhoon Yagi and focused on nine categories of buildings and structures that showed obvious damage (building envelopes, high-rise buildings, tall/steel structures, temporary buildings, agricultural greenhouse buildings, road infrastructure, photovoltaic structures, power and communication facilities, wind power generation systems), as well as coastal erosion and treefall conditions. More than 1,000 individual structures/sites were surveyed. A multi-source “space-air-ground” data acquisition approach was adopted: field studies were carried out to collect background information and record structural damage patterns and severity; handheld laser rangefinders and accelerometers were used to quantify damage parameters; satellite remote sensing and UAV(Unmanned Aerial Vehicle) aerial imagery were employed to analyze coastal erosion and treefall; questionnaire surveys and subjective perception assessments were applied to quantify wind-induced vibration comfort in high-rise buildings. For data processing, most surveyed objects were classified according to function, location distribution, and other characteristics, and disaster losses were graded to summarize damage patterns. Representative cases were selected for in-depth analysis of disaster causes. The investigation received support and guidance from the Hainan Meteorological Service, Hainan Provincial Department of Housing and Urban-Rural Development, Hainan Provincial Department of Transportation, Hainan Provincial Department of Emergency Management, and Hainan Provincial Department of Natural Resources and Planning. Substantial assistance during field visits and data collection was provided by the People’s Government of Dongying Town in Lingao County, Gengdushanfang, the Mei’ao Village Committee, and Shuichongpo Village in Ding’an County. Enterprises including Hainan Xinyi Mining Co., Ltd., Hainan Zhelian Steel Structure Group Co., Ltd., Hainan Holdings & Energy China Co., Ltd., Wenchang Luneng Hilton Hotel, Hainan Zhipu Agricultural Technology Development Co., Ltd., and Hainan Yabang Integrated Housing Co., Ltd. also offered active cooperation and support.　　The investigation results show that many meteorological stations recorded wind pressures exceeding the design load standards for buildings, and wind-speed amplification due to topographic effects was observed in some areas. For instance, the high-rise building cluster near Haikou Bay experienced a local wind-speed increase of 20%~30% due to the Venturi effect; the peak dynamic wind pressure on windward building envelopes exceeded 5 kPa (nearly 50% above the design load for conventional buildings). Existing building envelopes, temporary structures, power facilities, and agricultural greenhouse buildings exhibited insufficient resistance to super typhoons, indicating an urgent need to revise relevant construction codes in typhoon-prone regions. The sandy coastline in Wenchang showed shoreline retreat on the order of meters, necessitating heightened attention and the formulation of long-term protection strategies. Secondary hazards such as heavy rainfall and treefall severely impacted the service life of highways and urban roads; resilience should be enhanced through improved drainage systems and roadside tree planning. Treefall patterns were directly related to geographic location, surrounding built environment, and tree species; rational spatial planning can help reduce disaster losses. The disaster prevention and emergency response to Super Typhoon Yagi once again demonstrated that securing communications, transportation, and water and power supply is central to emergency management and plays a key role in reducing losses and casualties. It is essential to strengthen relevant standards and promote the application of new disaster prevention and mitigation technologies in these sectors. The impact area and damage severity of super typhoons are directly linked to geographical location, terrain, land use and other factors, exhibiting marked regional characteristics. Given that the two strongest typhoons on record to strike China both landfall in Wenchang, Hainan Province, causing enormous economic losses to Hainan Island, it is recommended to establish a Typhoon Disaster Prevention and Mitigation Research Center in Hainan Island. The center would systematically investigate the occurrence patterns of typhoon disasters, innovative technologies for disaster prevention, avoidance, mitigation and post-disaster recovery, as well as related laws, regulations and policy measures, while fostering international exchange and cooperation to support scientific decision-making by the government.

In order to improve the hydrophobic properties of coral aggregate mortar, a hydrophobically modified mineral powder was prepared by modifying mineral powder with polydimethylsiloxane (PDMS). Based on Modified Andreasen-Andersen (MAA) model and the response surface method, the mortar mix ratio was designed, and a hydrophobically modified coral aggregate mortar was developed. The effects of individually incorporating PDMS, individually incorporating hydrophobically modified mineral powder, and a combined addition of PDMS hydrophobically modified mineral powder on the hydrophobic properties and mechanical properties of the mortar were compared and analyzed. The hydrophobic mechanism was studied using X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. The test results show that the hydrophobically modified mineral powder was prepared using a PDMS content of 5%. The mix with 5% PDMS and 10% hydrophobically modified mineral powder showed excellent hydrophobic properties, achieving a contact angle of 123.4° and a water absorption of 0.16% after 8 h. Compared to the blank group, the compressive strength of the 5% PDMS group decreased by 37.7%. In contrast, the strength of the 10% hydrophobically modified mineral powder group increased by 14.5%, while that of the combined (5% PDMS + 10% powder) group decreased by 39.2%. PDMS improves the hydrophobicity of the material by forming a hydrophobic film on the surface of hydrated calcium silicate, and the hydrophobic modified mineral powder cuts off the water transport path by blocking the pore connectivity, thereby achieving the hydrophobic effect. PDMS reduces the compressive strength by reducing the content of hydrated calcium silicate, while the effect of hydrophobically modified mineral powder is the opposite. The negative effect of PDMS dominates the overall compressive strength.

To meet the growing demand for innovative high-performance green building materials in the construction industry, this study designs a novel sandwich panel composed of GFRP (glass fiber-reinforced polymer) skins and an aluminum honeycomb core filled with ultra-high performance recycled fine aggregate concrete (UHP-RFAC). The compressive and flexural behaviors of these panels were experimentally investigated, with emphasis on the effects of (1) GFRP skin thicknesses, (2) aluminum honeycomb core thicknesses, and (3) concrete infill on failure modes, compressive strength, and bending strength. Test results revealed that under axial compression, failure occurred in the core layer, whereas three-point bending tests induced failure in both the GFRP skins and the aluminum honeycomb. Filling the honeycomb with UHP-RFAC significantly enhanced the compressive and flexural strength of the panels. Moreover, increasing the thickness of either the GFRP skins or the honeycomb core further improved mechanical performance.

Hainan Island is located in the tropical marine monsoon climate zone, and the masonry structures of villages and towns on the island are exposed to the complex and harsh environments, such as high temperature, high humidity, high salt spray, and high ultraviolet rays. Because of the limitations of masonry mode and construction technology, under the action of random loads, the masonry structure houses in the place are easy to be damaged. Because they have been affected by the complex environment for many years, and the effective repair measures are lacked, there are greater safety hazards in a number of civil masonry houses, which seriously reduced their service life. Until now, the masonry houses are still the main form of the construction in Hainan villages and towns. In the report, Baoting County, Hainan Province was used as an example, the quality disease data of 1614 single-storey masonry houses in the region were counted, the failure forms and the possible causes of single-storey masonry structures in tropical island villages and towns were analyzed and summarized, and the mechanical properties of the masonry materials of typical active masonry structures were tested. The results indicated that within the length of service, the minimum strength retention rate and maximum strength retention of the red brick sample was 23.7%, 173.5%, respectively; the minimum strength retention rate and maximum strength retention of the steel sample was 55.9%, 112.4%, respectively.

In the report, the continuous spraying of Q235 steel for 1, 3, 7, 21, and 42 d with a neutral salt spray tank were performed to compare and analyze the macro/micro morphology changes, mass loss, surface strain field changes, and the degradation law of various mechanical properties (elastic modulus, yield strength, tensile strength, and strain after fracture) with the weight loss rate of Q235 steel after corrosion. The effects of the corrosion time on Q235 steel were also studied. The results showed that salt spray accelerated the formation and shedding process of the rust layer, the microstructure developed from sparse pitting to pitting, and then to honeycomb. The average corrosion rate decreased firstly, and then increased with the salt spray time. The mechanical properties had a linear relationship with the weight loss rate. With the extension of corrosion time, the high strain area became more dispersed, the surface strain field became more uneven, especially in the elastic stage and the strengthening stage. Salt spray reduced the strain difference at the fracture stage, and made the material brittle, and the macro fracture morphology changed from inclined fracture to step fracture.

To address the issue of brittleness and cracking in ordinary concrete speed bumps, this study proposes a modified rubber-steel fiber concrete material. Rubber particles were treated with KH560 solution, silica fume, and NaOH solution, and modified rubber-steel fiber concrete specimens were prepared. The study include compressive strength tests, full-field surface strain analysis, failure mode assessment, and Scanning Electron Microscope (SEM) analysis. The results indicate that the compressive strength of rubber-steel fiber concrete decreases gradually with an increasing rubber particles volume fraction. At 5% and 10% rubber content, all three modification methods enhanced compressive strength. Notably, silica-fume-modified rubber particles at a 10% volume fraction exhibited the highest average strain capacity on the full-field surface, with a maximum average horizontal strain of 1,900 me and a maximum average vertical strain of −3,100 me. Additionally, this modification significantly reduced specimen expansion and cracking. All three treatments effectively improved the interfacial bonding between rubber particles and the cement matrix.