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A new luminescent CdII compound, poly[[μ2-1,4-bis(1H-imidazol-1-yl)benzene]{μ2-5-[(3-carboxylphenoxy)methyl]isophthalato}cadmium(II)], [Cd(C16H10O7)(C12H10N4)] n or [Cd(HL)(1,4-bib)] n {H3 L is 5-[(3-carboxyphenoxy)methyl]isophthalic acid and 1,4-bib is 1,4-bis(1H-imidazol-1-yl)benzene}, I, has been synthesized successfully from CdII and a semirigid tricarboxylic ligand under hydrothermal conditions. Structure analysis shows that I is a two-dimensional structure with the point symbol {44.62}. The three-dimensional framework is constructed by O—H...O hydrogen bonds and π–π stacking interactions. Furthermore, the obtained CdII compound displays high solvent stability and excellent thermal stability, as shown by powder X-ray diffraction and thermogravimetry measurements. Studies of the luminescence properties reveal that compound I can act as a promising luminescent sensor for detecting FeIII cations and CrVI oxyanions with high selectivity and low detection limits (0.19 µM for Fe3+ and 1.13 µM for Cr2O7 2−), and is additionally free from the interference of other ions. The mechanism of selective quenching was studied by measuring the UV–Vis absorption of the host compound and the target analytes.

A new luminescent Cd

This paper presents a laboratory experimental study on particle breakage of sand subjected to friction and collision, by a number of drum tests on granular materials (silica sand No. 3 and ceramic balls) to investigate the characteristics of particle breakage and its effect on the characteristics of grain size distribution of sand. Particle breakage increased in up convexity with increasing duration of drum tests, but increased linearly with increasing number of balls. Particle breakage showed an increase, followed by a decrease while increasing the amount of sand. There may be existence of a characteristic amount of sand causing a maximum particle breakage. Friction tests caused much less particle breakage than collision tests did. Friction and collision resulted in different mechanisms of particle breakage, mainly by abrasion for friction and by splitting for collision. The fines content increased with increasing relative breakage. Particle breakage in the friction tests (abrasion) resulted in a sharper increase but with a smaller total amount of fines content in comparison with that in the collision tests (splitting). For the collision tests, the fines content showed a decrease followed by an increase as the amount of sand increased, whereas it increased in up convexity with increasing number of balls. The characteristic grain sizes D 10 and D 30 decreased in down convexity with increasing relative breakage, which could be described by a natural exponential function. However, the characteristic grain sizes D 50 and D 60 decreased linearly while increasing the relative breakage. In addition, the coefficients of uniformity and curvature of sand showed an increase followed by a decrease while increasing the relative breakage.

This study aimed to illustrate the seismic response and instability process of a double-row anti-slide pile-reinforced bridge foundation and gravel landslide. Selecting the gravel slope of Jiuzhai Valley along the under-construction Chengdu-Lanzhou high-speed railway as the site prototype, large-scale shaking table tests were first conducted at a similitude ratio of 1:70, with sine waves and El Centro waves as the seismic wave inputs. The amplitudes of the input seismic waves were increased, while the acceleration, dynamic earth pressure, and strain distribution were monitored in the gravel landslide. The dynamic response patterns of anti-slide pile-reinforced bridge foundations in gravel landslides were illustrated. The front-row and back-row anti-slide piles should be a reasonable distance from the bridge foundation. The response acceleration manifested an elevation amplification effect with an increasing elevation in the slope behind the anti-slide piles. Back-row anti-slide piles reinforcing the bridge foundation can reduce the effect of landslide thrust on the bridge foundation and maintain a uniform distribution of earth pressure behind the bridge foundation, mitigating seismic effects. The dynamic earth pressure peaked at the top of the bridge foundation and then decreased along the depth. The back-row anti-slide piles displayed greater resonance coupling and unloading effects before and after reaching the load-carrying limit, respectively. In seismic strengthening design involving bridge foundations and gravel landslides, when the earthquake-induced resonance coupling effect on inclined, loosely packed land masses is fully considered, pre-reinforcement measures (e.g., high-pressure grouting and anchor spraying) should be carried out on the gravel slopes.

Landslide events in Karakorum ranges are frequent and have already damaged local infrastructures and roads. In the hilly regions, landslide characterization and predicting its deposition pattern are essential for accurate engineering hazard assessment. To this end, numerical simulation models are commonly used tools. However, appropriate model parameters are often not available to predict and generate real landslide scenarios. This work describes the use of multidisciplinary techniques to estimate the model parameters for a slope prone to landslide and simulate the hazard level. The first important parameter, landslide boundary, and dynamics were estimated from temporal satellite images by identifying the areas with prominent deformations using the Interferometric Synthetic Aperture Radar (InSAR) technique. The susceptible subsurface strata volume and the possible landslide initiation depth were determined with the electrical resistivity method. In addition, voxel 3D electrical resistivity models were created to present the depth of the existing rupture and the nature of subsurface strata. The soil mechanical parameters were calculated during field visits and laboratory tests. The parameters adopted from different techniques helped simulate the susceptible landslide volume and initiation depth. These parameters are a critical factor in developing an accurate high-speed landslide model through numerical simulation. The applied methodology is vital to understand the dynamics of a particular slope and perform accurate engineering hazard assessment with numerical simulation. The results are essential to predict the potential deposition areas of the landslide event accurately, minimize the risk level, and take proactive mitigation measures.

This study aimed to illustrate the seismic performances of anti-slide pile-reinforced bridge foundations in landslides. Based on the anti-slide reinforcement project at Yousuotun along the Chengdu-Lanzhou high-speed railway under construction, shaking table tests were performed on a double-row anti-slide pile-reinforced bridge foundation and landslide model with a 1:40 similitude ratio. Given that the similitude law was satisfied, seismic waves with different frequencies and acceleration amplitudes were input as base excitations to monitor the responses of dynamic parameters: slope acceleration, earth pressure, and pile strain. The amplification effect of peak ground acceleration (PGA) was analyzed. The landslide thrust distribution characteristics and slope response processes were further studied to verify the seismic design of such bridge foundations in landslide-prone areas. The response acceleration of the slope subjected to seismic loads showed a nonlinear amplification “elevation effect”, “surface effect”, and “geological structure effect”. When the distance between the bridge foundation and the back-row anti-slide pile was small, the pier maintained a relatively large PGA amplification factor and was subjected to strong seismic loads. The landslide thrust was mainly borne by the upper part of the back-row anti-slide piles as its distribution changed from spoon-shaped to bow-shaped. Under high-intensity earthquake events, the load-bearing section of the bridge foundation should be strengthened at the sliding surface. Anti-slide piles can effectively limit the dynamic response of the landslide and weaken the seismic response of the slope. The results of testing this reinforcement are the first results proving that the seismic design of reinforced bridge foundations with anti-slide piles can be reliable.

Although weathered red mudstone (WRM) is widely distributed in the southwest of China, its suitability as a fill material for the subgrade bed of a high-speed railway (HSR) has not been comprehensively investigated. This paper presents the results of a field full-scale model testing of the cyclic loading and response of a railway track-subgrade system for the Dazhou-Chengdu Railway, where some WRM has been used in a newly designed subgrade structure. A control section of the HSR was also built using a traditional subgrade bed (Group A&B material) to compare the performances of the different sections. To better understand the dynamic characteristics and cumulative deformation of the two types of subgrade, the dynamic actions of different axle loads and different train speeds were simulated using specifically designed track-cyclic-loading equipment. The transverse and vertical distributions of the dynamic stress, dynamic displacement and acceleration of the track-subgrade system were measured and evaluated. The influence of the wheel axle load on the growth factor of the dynamic parameters, the vertical attenuation coefficient of the dynamic stress, and the effect of using WRM in the subgrade on the post-construction settlements were investigated. The tests enabled the development of cumulative settlement laws with railway loading for the two types of subgrade. Although the dynamic parameters and cumulative settlement of the WRM subgrade are always greater than those of better-quality material (Group A&B subgrade), they comply with HSR regulations. In conclusion, the results demonstrated that weathered red mudstone can be used as a filling material in the newly designed subgrade structure for HSRs.

The degree of mechanical reinforcement provided by plants depends upon its roots distribution in the soil and mechanical properties of the roots. The mechanical properties and distribution of root traits (root diameter and number) in the soil of the standing forest depends on the tree stem diameter. This variation of root traits with tree stem diameter is rarely investigated. Therefore, this research presents the effect of tree stem diameter on the distribution of roots within the standing forest of Cunninghamia in the Longchi forest area, Sichuan province, China. In this area, shallow landslides take place frequently. We investigated the root traits distribution for trees with different stem diameters, i.e., 220 mm, 320 mm, 450 mm, and 468 mm, to show the variation of roots distribution in the soil with stem diameter. The root architecture of the selected trees was studied by step excavation method of the root zone accompanied by measurement of roots physical parameters (roots number and roots diameter) and indices (roots area ratio (RAR), roots biomass (RB), and roots distribution (RD)). We measured the root&rsquo, s maximum tensile strength by performing root tensile tests in the laboratory. The field and laboratory-measured data were used to estimate the root cohesion by both the commonly used model Wu and Waldron Model (WWM) and Fiber Bundle Model (FBM). The results indicate that the tree stem diameter correlates with both the root distribution and the tensile strength. The roots indices and root cohesion increase with an increase in the diameter of the tree. Further, RAR decreases with depth and lateral distance from the tree stem, while the maximum values were observed in 10 cm depth. The relationship between roots diameter and roots tensile strength is established through power function. The average root cohesion estimated for a tree with stem diameter 220 mm is 23 kPa, 29 kPa for 320 mm, 54 kPa for 450 mm, and 63 kPa for 460 mm. This effect of stem diameter on the increase of soil shear resistance should be considered while evaluating the stability of slopes in standing forests. The comparison between WWM and FBM for investigated species suggests that WWM estimates the cohesion values greater than FBM by 65%.

Gyirong serves as an important channel to Chine-Nepal Economic Corridor, which is also the only land route for China-Nepal trade since the 2015 earthquake. However, the Gyirong corridor suffers from glacier-related debris flow from every April to September because of the complex topographic features and the changing climate. Therefore, a susceptibility map in response to precipitation and temperature change is timely, not only to ensure the safe operation of this corridor, but also to provide decision-makers a guidance for hazard mitigation and environmental remediation. Conventional method is difficult to consider and link the meteorological factors (e.g. temperature and precipitation), topographies, ecological, geological conditions all together to produce the susceptibility map, as such, machine learning is utilised to conduct the analysis. Logistic Regression (LR) and Support Vector Machine (SVM) were firstly applied to evaluate their efficiency and effectiveness of the performance of producing the susceptibility map. In order to improve the fitting and prediction accuracy (ACC), genetic algorithm - support vector machine (GA-SVM) and certainty factor - genetic algorithm - support vector machine (CF-GA-SVM) were conducted based on the initial analysis results of receiver operating characteristics curve (ROC) and ACC. Through the analysis, it can be seen that over 61% of the study areas have a high susceptibility to debris flow, requiring an intensive attention from the local government. To further optimise the computational time, when dealing with small amounts of sample data, SVM is more efficient than LR, but CF-GA-SVM can achieve the highest AUC (Area Under Curve) and ACC values, 0.945 and 0.800, respectively. Overall, CF-GA-SVM model presents a relatively high robustness according to sensitivity analysis.

As it is very difficult to construct conforming plate elements and the solutions achieved with conforming elements yield inferior accuracy to those achieved with nonconforming elements on many occasions, nonconforming elements, especially Adini’s element (ACM element), are often recommended for practical usage. However, the convergence, good numerical accuracy, and high computing efficiency of ACM element with irregular physical boundaries cannot be achieved using either the finite element method (FEM) or the numerical manifold method (NMM). The mixed-order NMM with background cells for integration was developed to analyze the bending of nonconforming thin plates with irregular physical boundaries. Regular meshes were selected to improve the convergence performance; background cells were used to improve the integration accuracy without increasing the degrees of freedom, retaining the efficiency as well; the mixed-order local displacement function was taken to improve the interpolation accuracy. With the penalized formulation fitted to the NMM for Kirchhoff’s thin plate bending, a new scheme was proposed to deal with irregular domain boundaries. Based on the present computational framework, comparisons with other studies were performed by taking several typical examples. The results indicated that the solutions achieved with the proposed NMM rapidly converged to the analytical solutions and their accuracy was vastly superior to that achieved with the FEM and the traditional NMM.

Background: Treatment of myoclonic seizures in myoclonic epilepsy with ragged-red fibers (MERRFs) has been empirical and ineffective. Guideline on this disease is not available. Additional trials must be conducted to find more suitable treatments for it. In this study, the antimyoclonic effects of monotherapies, including levetiracetam (LEV), clonazepam (CZP), valproic acid (VPA), and topiramate (TPM) compared to combination therapy group with LEV and CZP on MERRF, were evaluated to find a more advantageous approach on the treatment of myoclonic seizures. Methods: Treatments of myoclonic seizures with VPA, LEV, CZP, and TPM were reported as monotherapies in 17 MERRF patients from Qilu Hospital between 2003 and 2016, who were diagnosed through clinical data and genetic testing. After 1–4 months of follow-up (mean: 82.9 ± 28.1 days), 12 patients that exhibited poor responses to monotherapy were given a combined treatment consisting of LEV and CZP subsequently. The follow-up period was 4–144 months (mean: 66.3 ± 45.3 months), the effective rates of monotherapy group (17 patients) and combination therapy group (12 patients) were analyzed by Chi-square test. Results: The m.8344 A>G mutation was detected in all patients. There were four patients with partial response (4/17, two in the CZP group and two in the LEV group), ten patients with stable disease (10/17, six in the CZP group, three in the LEV group, and one in the TPM group), and three patients with progressive disease (3/18, two in the VPA group and one in the TPM group). Twelve of the patients with LEV combined with CZP showed a positive effect and good tolerance (12/12), eight of them demonstrated improved cognition and coordination. There was a significant difference between the monotherapy group and combination therapy group in the efficacy of antimyoclonic seizures (χ2 = 13.7, P < 0.001). Conclusions: LEV in combination with CZP is an efficient and safe treatment for myoclonic seizures in patients with this disease exhibiting the m.8344A>G mutation. Key words: Clonazepam; Levetiracetam; Myoclonic Epilepsy with Ragged-Red Fibers; Myoclonic Seizures

Blasting in high in situ stress fields is different from blasting at the earth’s surface because of the dynamic unloading effect in the former. In order to study the coupling of dynamic loading and dynamic unloading in the blasting process, the explicit finite element method and explicit-implicit finite element method are employed respectively to investigate the influence of high stress on blasting effects. The results show that the stress and strain change rules of the two methods are clearly different. The stress and strain change rates calculated by the explicit-implicit algorithm simulation are greater than the results simulated by the explicit finite algorithm. The radius of the blasting cavity calculated by the explicit-implicit finite element method is 0.015 m larger than that of the explicit finite element method. Based on the results of the explicit finite element method, a theoretical model is also established, which helps to clarify the effects of high in situ stress unloading when blasting in a high in situ stress field. The model shows that the maximum tensile radial displacement caused by high in situ stress dynamic unloading at the edge of the blasting cavity is 0.12 mm, and the dynamic unloading radial tensile effect can lead to rock failure. This research illustrates that high stress has a considerable influence on the blasting process and on rock-breaking effects. According to the findings, certain blasting engineering design suggestions are made.

Debris landslides are one of the most widely distributed types of landslides in the Wenchuan earthquake area. The hydro-geological structure characteristics are the fundamental basis for stability evaluation, performing protection and administration of a landslide. The rock and soil mass of a debris landslide was highly non-uniform and preferential seepage paths were normally developed in it. Therefore, in situ identification of the underground water seepage system became particularly important. Recently, investigations on the seepage paths of underground water in debris landslides were restricted to indoor model testing and site observation, which were far from meeting the actual demand for landslide prevention and mitigation. To locate the seepage paths, we conducted survey work on a debris landslide seated in the Xishan Village, Li County, Sichuan Province, China, by combing four different geophysical methods. They were multichannel analysis of surface wave (MASW), electrical resistivity tomography (ERT), ground penetrating radar (GPR) and microtremor survey method (MSM). The geophysical interpretation was verified with field engineering surveys and monitoring data. The results suggested that a dendritic pipe-network seepage system usually developed in debris landslides. Varisized infiltration pipes showed the characteristics of inhomogeneity and concentration of the seepage. This work highlighted that geophysical parameters (shear wave velocity Vs, dielectric constant ε and resistivity value ρ) could provide reliable qualitative and quantitative information about the colluvial layer, bedrock interface, potential sliding surface and underground water seepage system of a landslide. The optimum combination of geophysical methods was suitable to survey the hydro-geological characteristics of debris landslides in the Wenchuan earthquake area.\ud \ud

Water scarcity is influencing environmental and socio-economic development on a global scale. Pakistan is ranked third among the countries facing water scarcity. This situation is currently generating intra-provincial water disputes and could lead to transboundary water conflicts. This study assessed the future water resources of Astore basin under representative concentration pathways (RCP) 4.5 and 8.5 scenarios using fully distributed TOPographic Kinematic APproximation and Integration (TOPKAPI) model. TOPKAPI model was calibrated and validated over five years from 1999−2003 with a Nash coefficient ranging from 0.93−0.97. Towards the end of the 21st century, the air temperature of Astore will increase by 3°C and 9.6 °C under the RCP4.5 and 8.5 scenarios, respectively. The rise in air temperature can decrease the snow cover with Mann Kendall trend of −0.12%/yr and −0.39%/yr (p ≥ 0.05) while annual discharge projected to be increased 11% (p ≤ 0.05) and 37% (p ≥ 0.05) under RCP4.5 and RCP8.5, respectively. Moreover, the Astore basin showed a different pattern of seasonal shifts, as surface runoff in summer monsoon season declined further due to a reduction in precipitation. In the spring season, the earlier onset of snow and glacier melting increased the runoff due to high temperature, regardless of the decreasing trend of precipitation. This increased surface runoff from snow/glacier melt of Upper Indus Basin (UIB) can potentially be utilized to develop water policy and planning new water harvesting and storage structures, to reduce the risk of flooding.

In this chapter, the physical and chemical properties of natural fibers (i.e., natural moisture content, specific gravity, breaking tensile strength, breaking strain, cellulose, hemicellulose, lignin and ash) were examined for their influences in the soil reinforcement. A total of 11 factors including soil moisture content, soil density and fiber percentage were evaluated by using the Bayesian nonparametric general regression (BNGR) method. The robustness of the BNGR algorithm was validated using k-fold cross-validation. A parametric study was carried out to unveil the effects of these input variables. The results indicated that a higher fiber percentage or larger soil density induces higher reinforcement effect. Besides, the cellulose in a natural fiber is found to have a significant effect on the unconfined compressive strength (UCS) followed by the ash. With respect to the physical properties, the breaking strain is found to be highly correlated with the UCS, while the effects of fiber natural moisture content, specific gravity and breaking tensile strength are less significant parameters.

The rapid evaluation of post-earthquake landslides and unstable slopes (whether they will be revived by aftershocks) is a key task in the post-earthquake emergency response phase. Stability chart and Newmark model is generally used for rapid evaluation of seismic stability of soil slopes. In this study, a novel method for directly estimating static, pseudo-static safety factors and critical accelerations of soil slopes is proposed; this method overcomes the limitations of stability chart and Newmark model. Based on finite element limit analysis and Mohr-Coulomb criterion, safety factors and critical acceleration of typical slope models are studied via the parametric method. First, a stability chart of safety factors under static and pseudo-static states is calculated by finite element limit analysis. Correspondingly, the critical acceleration under static condition is obtained. Next, the seismic weighting factor and slope angle weighting factor are put forward, and a rapid evaluation model of safety factors is established. Finally, according to the correlation between safety factors and critical acceleration under static conditions, a rapid evaluation model for critical acceleration is proposed. The proposed method is compared with the results of the Newmark model and finite element limit analysis. The results show that the prediction accuracy of the proposed method is closer to the results of finite element limit analysis than those of Newmark model. The proposed seismic stability model is reliable and efficient and can be used to evaluate the stability of soil slope at the initial design stage and provide reference for further seismic design.

As a useful tool to simulate the movement of granular materials, the Particle Flow Code is used to analyze the dynamic process of the Xinmo landslide, including: disintegration, entrainment, granular flow and accumulation. The microparameters of the landslide rock mass were calibrated with uniaxial compression and landslide deposition simulations. The results show that the kinetic characteristics of the collapse mass were more sensitive to the bond strength than to the friction coefficient. For the colluvium on the runout path, the influence on the kinetic characteristics was insignificant in the case of the lower bond strength and friction coefficient. The whole process lasted approximately 100 s, and the main sliding time was 65 s. The peak velocity was 72.4 m/s, and the maximum displacement was approximately 2.5 km. The results indicate that the gravitational potential energy was mainly converted into friction energy and kinetic energy in the acceleration stage. However, the proportion of the collision energy increased gradually in the deceleration stage. The entrainment effect plays an important role in the Xinmo landslide movement. The high gravitational potential energy of the collapse mass was the basis of the high mobility, and the mobility was further enhanced because of the entrainment effect.

Vacancy-type defects play an important role in the metal materials deformed by severe plastic deformation (SPD). The present work use positron annihilation lifetime spectroscopy (PALS) to test the vacancy-type defects in aluminium alloys processed by equal channel angular pressing (ECAP) and accumulative roll bonding (ARB). ECAP at room temperature and cryogenic temperature was conducted to AA1050 and ARB with 200 � C pre- heating was conducted to AA1050 and AA6061 to produce laminated AA1050 sheets, AA6061 sheets and AA1050/AA6061 composites. High fraction of vacancy-type defects were detected in all the deformed samples. Vacancies associated with dislocations and bulk mono-vacancies have been identified in RT-ECAP deformed samples. Three types of vacancy-type defects, vacancies associated with dislocations, bulk mono-vacancies and bulk di-vacancies, have been identified in the CT-ECAP processed samples. The ARB process is more efficient in grain refinement and strengthening. However, the accumulation of vacancy-type defects in ARB deformation seems less efficient. Vacancies associated with dislocations are the major vacancy-type defects for ARB processed AA1050 sheets but there exist some bulk mono-vacancies. However, most of the vacancy-type defects in the ARB processed AA6061 are vacancies associated with dislocations. A very small fraction of bulk mono-vacancies can be extracted but it is so small that it can be neglected. The lifetimes of ARB processed AA1050/AA6061 composites are generally in between the values of AA1050 sheets and AA6061 sheets. Voids were not detected in neither of the samples.

The ground-penetrating radar (GPR) has been widely used in many applications. However, the processing and interpretation of the acquired signals remain challenging tasks since an experienced user is required to manage the entire operation. In this paper, we present an automatic classification system to assess railway-ballast conditions. It is based on the extraction of magnitude spectra at salient frequencies and their classification using support vector machines. The system is evaluated on real-world railway GPR data. The experimental results show that the proposed method efficiently represents the GPR signal using a small number of coefficients and achieves a high classification rate when distinguishing GPR signals reflected by ballasts of different conditions.

In this paper, moisture migration in loess considering temperature effect is studied by tests on unsaturated loess samples with different densities and initial moisture contents. Test results reveal that obvious changes in moisture content distribution in a loess sample can be observed after temperature difference is exerted on the two ends of the sample. Moisture content at the cold end increases and that at the hot end decreases. Under the effect of temperature difference, moisture content difference at the two ends of a soil sample is related to the initial moisture content, soil density, and magnitude of the temperature difference. Generally speaking, larger temperature differences and smaller soil densities result in more obvious moisture migration and larger moisture content differences at the two ends of the soil sample. When the initial moisture content is large, the moisture content difference caused by a temperature difference is small; when the initial moisture content is small, the moisture co...

Soil nailing is the most popular technique for stabilizing newly formed and existing sub-standard slopes in Hong Kong because of its economic and technical advantages. The nail–soil interface shear resistance is an important parameter in design of soil nailed structures. A three-dimensional finite element model was established and used for simulating soil nail pull-out tests. The finite element model was verified by comparing simulated results with measured data. The agreement between the experimental and simulated results in terms of both average pull-out shear stress and stress variation was very good. Using this finite element model, a parametric study was carried out to study the influences of the overburden pressure and soil dilation angle on the soil nail pull-out resistance. The simulated peak pull-out resistance was not directly related to the overburden pressure, which was coincident with the observations in laboratory pull-out tests. The simulated pull-out resistance increased significantly with the increase in dilation angle of the shearing zone. This analysis indicated that the constrained dilatancy of the nail–soil interface and the soil surrounding the nail contributed a lot to the development of peak pull-out resistance.

Soil nailing has been widely used in many places in the world in the last two decades because of its technical and economical advantages. The nail–soil interface shear strength is an important parameter in soil nail design. This parameter is governed by a number of factors, among which the influence of the overburden pressure (or soil depth) is the most controversial. There are differing views concerning the effect of overburden on the nail–soil interface shear strength. In order to examine the influence of the overburden pressure, a series of laboratory pullout tests on soil nails installed in compacted completely decomposed granite fill have been conducted using two pullout boxes. Numerical simulations have also been carried out and the results are compared with the pullout test data. The procedures of the pullout tests and new features of the pullout boxes used are briefly described. Changes of the vertical stress in soil close to the nail throughout the course of soil nail installation and pullout are...

The nail–soil interface shear strength is a key parameter in the design and stability assessment of soil nailing systems. A number of factors will influence the nail–soil interface shear strength. Among these factors, the degree of saturation (Sr) of the soil is an important one especially for permanent soil nail structures. To study the influence of Sron soil nail pull-out shear resistance, a series of laboratory pull-out tests have been conducted on soil nails in compacted completely decomposed granite (CDG) fill prepared to different Sr. The tests were conducted using two specially designed pull-out boxes (with same specifications). In the near-saturated tests, a high Sr(about 98%) was achieved using two special features of the apparatus: a waterproof front cap and back-water pressure pipes at the bottom of the pull-out box. Test results showed that the nail–soil shearing plane migrated outwards into the soil when the Srof the soil increased. Also, peak pull-out strengths of soil nails were strongly influenced by the Srof the soil. Among the tested Sr, the highest values of peak pull-out shear strength were obtained at Srvalues between 50% and 75%.

The soil CO2 emission is recognized as one of the largest fluxes in the global carbon cycle. Small errors in its estimation can result in large uncertainties and have important consequences for climate model predictions. Monte Carlo approach is efficient for estimating and reducing spatial scale sampling errors. However, that has not been used in soil CO2 emission studies. Here, soil respiration data from 51 PVC collars were measured within farmland cultivated by maize covering 25 km2 during the growing season. Based on Monte Carlo approach, optimal sample sizes of soil temperature, soil moisture, and soil CO2 emission were determined. And models of soil respiration can be effectively assessed: Soil temperature model is the most effective model to increasing accuracy among three models. The study demonstrated that Monte Carlo approach may improve soil respiration accuracy with limited sample size. That will be valuable for reducing uncertainties of global carbon cycle.

The aim of this study was to investigate the value of T(2) (*)-weighted gradient echo imaging (GRE T(2) (*)-WI) for the detection of familial cerebral cavernous malformation (FCCM). Twenty-six members of 2 families with FCCM were examined using computed tomography (CT), conventional magnetic resonance imaging (MRI) and GRE T(2) (*)-WI sequences. We identified 12 cases of FCCM using GRE T(2) (*)-WI sequences. These 12 patients had multiple lesions (mean 23). The lesions were most commonly located in the ganglia. Other areas included the cortex-subcortex, thalamus, cerebellum and brainstem. These lesions appeared as a reticulated core of mixed signal intensity with a surrounding rim of decreased signal intensity representing hemosiderin from previous hemorrhages. The mean numbers of lesions and cases of FCCM identified by various conventional MRI sequences were 5-17 and 3-9, respectively. Conventional MRI examination involved T(1)-weighted imaging (T(1)WI), T(2)-weighted imaging (T(2)WI), T(2)-fluid-attenuated inversion recovery (T(2)Flair), diffusion-weighted imaging (DWI) and spin-echo imaging (SE) sequences, in that order. The numbers of lesions identified by MRI were fewer than those identified by GRE T(2) (*)-WI. CT only identified 3 cases with large lesions combined with hemorrhage and calcification. These findings suggest that GRE T(2) (*)-WI is the first choice when diagnosing FCCM compared with CT and conventional MRI.

Ground penetrating radar has been widely used in many areas. However, the processing and interpretation of acquired signals remains a challenging task since it requires experienced users to manage the whole operations. In this paper, we propose an automatic classification system to categorise GPR signals based on magnitude spectrum amplitudes and support vector machines. The system is tested on a real-world GPR data set. The experimental results show that our system can correctly distinguish ground penetrating radar signals reflected by different materials.