The slope along north section of the BeijingZhuhai expressway in Guangdong province is mainly limestone bedding slope. To reveal the relationship between the deformation failure modes of limestone slopes and the bedding angle of the strata, a targeted experimental research and theoretical analysis has been carried out, which provides a basis for the stability criterion of bedding limestone slope. In this paper, the slope samples along the expressway are selected and grouped according to different layer angle h, and the Brazilian disc splitting test has been carried out. According to the experiment, it is found that with the change of limestone bedding angle, five failure modes would occur: À When the bedding angle is between 0°and 30°, pure tensile failure occurs.`30°-45°, tensileslip type failure.´45°-75°, the slip-crack type failure.7 5°-90°, the slip type failure.˜h = 90°, the compression type failure. And the tensile strength of the limestone decreases as the bedding angle h changes from 0°to 90°. Secondly, the criterion of bedding limestone slope's overall slip failure and the partial slip-crack failure is deduced. The critical slope height equation of overall slip failure and the critical slope length equation of partial slip-crack failure are obtained. Finally, we have taken an application in a limestone slope which located in Guangdong Province Beijing-Zhuhai expressway north section. The theory agrees well with the actual stability of bedding limestone slope.

The Marshall method is today considered the standard method of asphalt mixture design for practical engineering applications. By using this method, engineering designers reap the benefits of its easy implementation and inexpensive equipment requirements. However, the Marshall method also has shortcomings and limitations, such as the difficulty in simulating the actual working conditions of a road under heavy load. Therefore, it is desirable to develop alternative methods for designing asphalt mixtures that can simulate the actual conditions under which the road will be used and so enable technically superior road construction. The emergence of the gyratory testing machine (GTM) method represents a new direction in asphalt mixture design that could plan more effectively for heavy loads in a hot and humid environment. In this paper, the two design methods are compared on the basis of the oil-stone ratio, high-temperature stability, water stability, and rutting resistance of the mixes they recommend. We put forward an improved GTM method suitable for the high temperatures and heavy traffic in Guangdong Province. This work provides a foundation for the large-scale popularization and application of the GTM method.