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Potential earthquake-induced damage to overlapped tunnels probably occurs during the operation and maintenance of mountain tunnel engineering, especially in the seismically active zone. This study investigated the dynamic response and the failure characteristics of the parallel overlapped tunnel under seismic loadings by employing shaking table tests. The failure mode of the parallel overlapped tunnels was analyzed through macroscopic test phenomena. The dynamic responses of the surrounding rock and tunnel lining were evaluated by acceleration and dynamic strain, respectively. In particular, wavelet packets were used to investigate the spectrum characteristics of the tunnel structure in depth. The failure process of the model can be divided into three stages. The upper-span and the under-crossing tunnels showed different failure characteristics. Additionally, the lining damage on the outer surface of the tunnel mainly occurred on the right side arch waist and the left side wall, whereas the lining damage on the inner surface of the tunnel mainly appeared on the crown and invert. Wavelet packet energy results showed that the energy characteristic distributions of the upper-span and the under-crossing tunnels were not consistent. Specifically, the energy eigenvalues of the crown of the upper-span tunnel and the invert of the under-crossing tunnel were the largest, which should be considered to be the weak parts in the seismic design.

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...

This paper explores the reasonable proportion of guest soil in bio-slope-engineering by means of proportional experiments. In the experiment, rubble and improved materials such as peat and water-retaining agent were selected to study the effect of peat and water-retaining agent content on moisture constant, permeability coefficient and water absorption rate of guest soil.The measurements showed that peat and absorbent agent improve effective water capacity and water absorption speed of guest soil, thus guest soil absorb and hold more effective water; however, with the increase of peat content, wilting moisture capacity of guest soil will increase and its permeability coefficient will also enlarge, which is a disadvantage to plants survival in drought conditions and slope stability in rainy seasons. According to guest soil’s proportional experiments and field test, the favorable amount of rubble, peat, absorbent agent and aggregate agent, is 80%, 20%, 1.0‰ and 1.0‰, respectively, and the reasonable content of fertilizer in guest soil is 100 g/m2. The results may guide the design and construction of Guest soil spraying for bio- slope-engineering.

With the steady development of the development of the western region in China, the construction of mountain highways has developed rapidly, and the soil-rock mixed filler, as an excellent filler, is widely used in the subgrade filling of mountain highways. Unlike ordinary fine-grained soil, the source of the soil-rock mixtures (S-RMs) is not unique, and the particle size difference is large and the water content is not uniform, resulting in very complicated mechanical properties. But the current highway embankment codes are still mainly established on the fine-grained soil. It is not fully applicable to soil-rock filled embankment. Based on soil-rock filled embankment engineering practice, this research uses a large-scale direct shear test to research the mechanical characteristics of the S-RMs with different maximum particle diameters. According to the large-scale direct shear test of S-RMs with different maximum particle diameters, the shear displacement vs shear stress curve, shear dilation, and strength characteristics with maximum particle diameter were analyzed. Results demonstrate that whether secondary hardening occurs mainly depends on the normal stress and the maximum particle diameter of the filler. At different maximum particle diameters, the horizontal displacement vs vertical displacement curves of the S-RMs can be roughly divided into continuous shearing and beginning of shearing and quick dilation. And the shear strength increases with the increase of the maximum particle diameter. Moreover, the cohesion decreases first and then increases with the increase of the maximum particle diameter, and the internal friction angle increases with the increase of the maximum particle diameter. Therefore, some RBs with large particle diameter added to filler can effectively improve the shear strength of the S-RMs, which may be valuable for realistic engineering.

This study was designed to develop a drug-in-adhesive (DIA) type transdermal drug delivery system (TDDS) for D-threo-methylphenidate (D-threo-MP) that could be further developed for treating Attention-Deficit/Hyperactivity Disorder (ADHD) in children. During initial formulation optimization, three formulation factors, i.e., different adhesives, permeation enhancers and drug loading of D-threo-MP were screened using vertical Franz diffusion cells across newborn pig skin. A patch containing 15% (w/w) D-threo-MP in DURO-TAK®87-4098 was considered as an optimum patch which was selected for in vivo studies. The optimum D-threo-MP patch pharmacokinetic parameters were determined in Sprague Dawley (SD) rats and bama miniature pigs (Sus scrofa domestica) after application of transdermal patches, intravenous (i.v.) injection or oral administration. The absolute bioavailability and the relative bioavailability of D-threo-MP DIA patch in the SD rats model were 53.4% and 218.8%, respectively, and the relative bioavailability was 83.4% in the bama miniature pigs model. In this study, we showed that the optimized D-threo-MP patches could be further developed for treating Attention-Deficit/Hyperactivity Disorder (ADHD) in children.

In this study, the occurrence and distribution patterns of eight organophosphate esters (OPEs) were investigated in urban and rural surface water in a typical cosmopolitan city: Shanghai, China. In addition, concentration levels and removal efficiencies of seven sewage treatment plants were analyzed. The OPEs concentrations detected in urban rivers were significantly higher than those detected in rural rivers. Total OPEs ranged from 185.4 to 321 ng L−1 in rural surface water and from 340 to 1688.7 ng L−1 in urban, with an average of 221.8 ng L−1 and 850.2 ng L−1, respectively. Compared with other studies published in the world, the OPEs contamination in surface river water in Shanghai was at a moderate level. Furthermore, the potential sources of OPEs in urban surface water were investigated, and the results indicated that OPEs in urban surface water mainly came from three potential sources. In rural surface water, the OPE concentrations were uniformly distributed, so OPEs in rural surface water may came from nonpoint source pollution. Last, a preliminary environmental risk assessment and health risk assessment were conducted. The results showed low environmental risks at all sampling sites (except for sampling point R7: medium risk for algae) for the three aquatic organisms (algae, daphnia, and fish). Health risk assessment indicated a noncarcinogenic risk for diverse human groups for ƩOPEs.

From 2000, people use the ecological protection to reinforce rock slopes. These ecological protection methods not only can reduce the usage of concrete, but also can restore the degraded ecosystem of slopes. With the rapid development of infrastructures, many materials for ecological protection have been created. However, there are many defects in these materials, such as expensive price, weak strength in early period, easily slide or been eroded when encountered with rainfall. These defects are the problems awaiting solution in the development of slope ecological protection. In this paper, the author attempts to use cement as adhesive in a new material for the ecological protection, and carry out laboratory tests and field tests to verify the feasibility and reliability of this material. Based on existing research and the testing results, the author proposed the prescription of this new material, which can satisfy the survival requirement of vegetation on the slopes, lower costs and enhance the strength in early period of ecological protection as well.

A chiral UFLC-MS/MS method was established and validated for quantifying d-threo-methylphenidate (d-threo-MPH), l-threo-methylphenidate (l-threo-MPH), d-threo-ethylphenidate (d-threo-EPH), l-threo-ethylphenidate (l-threo-EPH) and d,l-threo-ritalinic acid (d,l-threo-RA) in rat plasma over the linearity range of 1-500ng/mL. Chiral separation was performed on an Astec Chirobiotic V2 column (5μm, 250×2.1mm) with isocratic elution using methanol containing 0.003% ammonium acetate (w/v) and 0.003% trifluoroacetic acid (v/v) at a flow of 0.3mL/min. All analytes and IS were extracted from rat plasma by a one-step liquid-liquid extraction (LLE) method. The intra- and inter-run accuracies were within 85-115%, and the intra- and inter-run precision were

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