A bearing capacity estimation method for bridge piles was developed. In this method, the pulse echo test was used to select the intact piles; the dynamic stiffness was obtained by the impulse transient response test. A total of 680 bridge piles were tested, and their capacities were estimated. Finally, core drilling analysis was used to check the reliability of this method. The results show that, for intact piles, an obvious positive correlation exits between the dynamic stiffness and bearing capacity of the piles. The core drilling analysis proved that the estimation method was reliable.

No abstract

Mediated social touch has the potential to enhance our interactions with machines and with each other. We present three wearable tactile devices that generate affective haptic sensations via three localised skin stretching modalities; pinching, squeezing, and twisting. The Pinch device is adhered to the skin of the forearm, generating pinching sensations in three locations. The Squeeze and Twist devices are wristbands that elicit squeezing and twisting sensations on the skin of the wrist. All of these devices are powered by shape memory alloy actuators, enabling them to be quiet, lightweight and discreet wearable interfaces, unlike their vibrotactile or servo-motor driven counterparts. We investigate the potential for these devices to be used in mediated social touch interactions by conducting preliminary psychometric tests measuring affective response. The Pinch device and Squeeze wristband were found to simulate positive affective touch sensations, particularly in comparison to vibrotactile stimuli.

Firefighter uniform made of various flame retardant materials is put as the object. Analyzing the thermal protective performance of different composite structures covering outer fabrics, lagging materials and comfortable layer materials, discuss the best combination of supporting structures. Adoption flash fire simulation, verify the integrated prevention ability of firefighter uniform. The matching of different levels has a significant impact on the thermal protective performance, first the outer layer, then comfortable layer and thermal protective coating. Although inherent fire resistant fiber for the main material of the outer fabric has better durability and thermal protective performance, the fire might experience obvious contraction which leads to embrittlements. For insulation flocculus, the ratio of aramid fiber 1313 and aramid fiber 1414 at 9:1 has excellent thermal insulation. For comfortable layer, inherent fire resistant fiber has no notable effect on the clothing’s overall thermal protection performance; the polysulfonamide fiber is a relative better choice.

With the growing number of tunnels in high-latitude and high-altitude areas, freezing damage is all the more obvious. In traditional insulation layer method, insulation layer is laid in the tunnel to prevent invasion of cold air by taking advantage of its low thermal conductivity. However, due to its narrow temperature adaptation range and high construction and maintenance costs, this method cannot completely solve the problem of tunnel freezing damage. To solve this problem, this paper proposes tunnel air curtain insulation system which can generate electricity using solar energy. Based on parameters such as indoor air temperature and wind velocity in the thermal insulation room, on the one hand, it intelligently controls running sets of air curtain, jet flow angle, and velocity, prevents invasion of the external cold temperature into the tunnel, so that the tunnel maintains an interior temperature above 0°C. On the other hand, it intelligently diagnoses air curtain machine to provide system fault warning, so that the system keeps safe and reliable operation. The results show that air curtain technology can effectively solve the problem of tunnel freezing damage in cold areas; multiple air curtains in series connection provide better barrier efficiency. From the measured data and calculation results of Lafashan tunnel, it can be seen that an air curtain is installed at the tunnel portal with jet speed of 22.7 m/s and temperature of 35.24°C, which can meet the tunnel without freezing damage when the external temperature is −10°C, and the external wind speed is 2 m/s, providing a new method for tunnel insulation technology in cold area.