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Due to the ignorance of the influence of frozen soil during the design period, the frost damage of subgrade in Datong-Junggar Railway was serious. The improvement scheme of frost damage was researched. However, the research based on the existing project was few, and previous improvement schemes could have an impact on the normal operation of railway system. Datong-Junggar Railway has undertaken the important task of transporting coal resources for China since its normal operation. To ensure normal operation of existing railway, the heating hole scheme was investigated by finite element simulations. The embedding spacing, the heating hole temperature and the embedding depth were analyzed. Based on the simulated results and on-site conditions, the design scheme of the heating hole (embedding spacing: 1.0 m, the heating hole temperature: 30°C and embedding depth: 70 cm) was proposed. Finally, the on-site monitoring in Qianshimen was taken to verify the feasibility of the heating hole scheme. Under the continuous energizing condition, the ground temperature remained basically stable even though the temperature had dropped to −7°C. The research results could enrich the design schemes for frost damage in cold regions from the aspect of ground temperature control.

Pervious concrete, extensively applied in sustainable urban drainage systems, is prone to clogging. From the perspective of the clogging particle size relative to the pore size, clay partic...

Affected by the site construction conditions, the measurement passes of the Taihang Expressway K8 + 105 ∼ K8 + 341 (K8 worksite) in the Taihang Expressway did not meet the requirements of data analysis, and the quantity of the control points was insufficient so that the linear correlation between the dynamic deformation modulus () and the vibratory compaction value (VCV) was not strong. Therefore, the target value of VCV cannot be used to diagnose the E v d compaction quality of soil-rock filler. This paper analyzes the roller measurement VCV value and in situ measurements E v d value separately. Results reveal the difference between the VCV mean measured in the last two passes and the standard deviation of the measured VCV mean in the last pass are used as the main basis for the actual compaction quality. In addition, the E v d mean in the last rolling can be used as an auxiliary judgment basis for the quality control of the compaction.

With deep-buried depth, large span, high geo-stress, complex geological conditions, and its large sections, the deformation behavior of the Gaopo Tunnel is a complex three-dimensional problem. To reveal the deformation behavior of the tunnel and evaluate the current support scheme, this paper establishes a three-dimensional model by benching tunneling method, and compares the monitoring data to analyze the deformation behavior of the surrounding rock and the variation of the stress field in the support structure. The results demonstrate that the rock inclination angle is 4° to 10°, the micro-dip layered structure, which is the main factor for the asymmetric deformation behavior of soft rock tunnel with large section passing through coal seams. The maximum displacement of surrounding rock and the maximum stress of the supporting structure are within the safe range in current scheme. Furthermore, some measures are summarized, which may provide some reference for similar engineering in the future.

Based on direct shear tests of soil samples with roots, the empirical formula of roots’ contribution to soil’s shear strength is summarized. In consideration of the effects of sliding surface depth, sliding mass width, sliding mass shape and roots, shallow slope stability analysis method for vegetated slope is suggested by mechanical equilibrium analysis of shallow sliding mass. According to the analysis of factors affecting shallow slope stabilization, it is shown that the factor’s importance descending order is sliding mass width, sliding surface depth and sliding mass shape in turn. Results of shallow slope stability analysis proposed by the paper are reasonable in comparison to the plane analysis method because more factors are taken into account. INTRODUCTION Numerous researchers have verified that plant roots can increase the shear strength of shallow soils, thereby enhance the stability of shallow slope ( e.g., Gray 1978; Wu 1979; Waldron 1981; Abe 1991). Many researchers have also derived various analytical models of soil-root interaction and shallow slope stability. However, they are mostly focused on the influence of vertical roots on shallow slope stability, and analyze the shallow slope stability by the plane method (e.g., Koler 1998; Sidle 1992; Ekanayake 1999; Zhao 2006; Qi 2006; Deng 2007). In fact, vertical roots can not reach the failure surface, therefore, they do not significantly improve the stability of shallow slope in most cases. In recent years, people have realized that lateral roots can improve the stability of shallow slope (e.g. Zhou 1997). Nevertheless, the analytical method is far from mature. We summarize the empirical formula of roots’ contribution to soil’s shear strength, then put forward shallow slope stability analysis method for vegetated slope according to mechanical analysis of shallow sliding mass. INFLUENCE OF PLANT ROOTS ON SOIL’S SHEAR STRENGTH Direct shear tests and results Prior to the test, we screen sandy clay with 2 mm soil samples sieve, then put sieved soil into different pots and compact them, finally remodel the soil by water addition. In