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Clinically, pentothal sodium has been widely used for primary and general anesthesia induction. Also, it has been used to effectively inhibit convulsion. Pentothal sodium has a strong inhibitory effect on the respiratory center, excessive drug administration, and rapid dose rate that cause death of experimental animals on the respiratory depression. This study used a modified pentothal sodium solution to investigate its anesthetic effect. The pentothal sodium solution was modified based on pentothal sodium upon additions of magnesium sulfate, propylene glycol, and pure ethanol. The anesthetic effect of the modified pentothal sodium on Sprague–Dawley (SD) rats was investigated by comparing traditional pentothal sodium and ketamine; 60 SD rats were randomly divided into three groups. Each group was treated with traditional pentothal sodium, modified pentothal sodium, or ketamine, respectively, via intraperitoneal injection. The symptoms of experimental rats were observed, and onset time and anesthetic time were both recorded. The data were analyzed using statistical software. There were no significant differences in onset time and anesthetic time between the three groups. The variation of onset time and anesthetic time of the group treated with modified pentothal sodium was shorter than that of the other two groups. Furthermore, the number of anesthetic rats after the first injection was significantly higher than that of the other two groups. The modified pentothal sodium is capable of providing a stable anesthetic effect. The function and effect are much better than traditional pentothal sodium and ketamine.

Tunnel boring machines (TBMs) are widely used in tunnel engineering because of their safety and efficiency. The TBM penetration rate (PR) is crucial, as its real-time prediction can reflect the adaptation of a TBM under current geological conditions and assist the adjustment of operating parameters. In this study, deep learning technology is applied to TBM performance prediction, and a PR prediction model based on a long short-term memory (LSTM) neuron network is proposed. To verify the performance of the proposed model, the machine parameters, rock mass parameters, and geological survey data from the water conveyance tunnel of the Hangzhou Second Water Source project were collected to form a dataset. Furthermore, 2313 excavation cycles were randomly composed of training datasets to train the LSTM-based model, and 257 excavation cycles were used as a testing dataset to test the performance. The root mean square error and the mean absolute error of the proposed model are 4.733 and 3.204, respectively. Compared with Recurrent neuron network (RNN) based model and traditional time-series prediction model autoregressive integrated moving average with explanation variables (ARIMAX), the overall performance on proposed model is better. Moreover, in the rapidly increasing period of the PR, the error of the LSTM-based model prediction curve is significantly smaller than those of the other two models. The prediction results indicate that the LSTM-based model proposed herein is relatively accurate, thereby providing guidance for the excavation process of TBMs and offering practical application value.

Crack propagation can gradually reduce the strength of the rock and eventually result in rock failure. Coupling effect of stress and seepage in fracture could accelerate the rock failure process. In this work, a set of water sealing device is developed to apply different fluid pressures in the pre-existing fracture in specimens made of rock-like material. We have carried out uniaxial compression tests on specimens at different pre-existing flaw dip angles (30°, 45°, and 60°) coupled with fluid pressures in the fracture. Through laboratory experiments and numerical simulations, we find that without fluid pressure in the pre-existing flaw, wing cracks and secondary cracks appear at the pre-existing flaw tips. With the increase of the fluid pressure in the flaw, the propagation of secondary cracks is restrained, no secondary cracks appear at the flaw tips. The increase of fluid pressure accelerates the wing crack propagation, inhibits the secondary cracks, and causes the specimen to undergo tensile failure. Compared with the specimen without the fluid pressure in the flaw, the fluid pressure in the flaw promotes wing crack initiation and propagation, and causes the initiation stress of the wing cracks and the peak strength of the specimens to decrease gradually. With or without fluid pressure in the fracture with the increase of the flaw dip angle, the initiation stress of wing cracks and peak strength of the specimen first decrease and then increase. When the pre-existing flaw dip angle is 45°, the peak strength and the initiation stress are the lowest.

The outbreak of 2019 novel coronavirus disease (COVID‐19) has posed a grave threat to the global public health. The COVID‐19‐induced infection is closely related to coagulation dysfunction in the affected patients. This paper attempts to conduct a meta‐analysis and systematically review the blood coagulation indicators in patients with severe COVID‐19. A meta‐analysis of eligible studies was performed to compare the blood coagulation indicators in patients with severe and nonsevere COVID‐19. PubMed, Embase, Web of Science, and the Cochrane Library were searched for studies published between 1 December 2019 and 7 May 2020. A total of 13 studies with 1341 adult patients were enrolled in this analysis. Platelet (weighted mean difference [WMD] = −24.83, 95% confidence interval [CI]: −34.12 to −15.54; P, Highlights Coagulation dysfunction affects the prognosis of COVID‐19 patients.Lower platelet, higher d‐dimer and fibrinogen indicate increased severity risk in COVID‐19 patients.No difference in PT and APTT is evident between severe and non‐severe COVID‐19 patients upon admission.

Corrosion resistance and durability are important performance features for grouting materials in underground engineering. The grouts based on ordinary Portland cement are difficult to solve water inrush disasters. To solve these problems, a new type of sulphoaluminate-cement-based Composite Grouting Material (CGM) has been developed. In this research, the chemical corrosion mechanism was analyzed, and the durability and anti-corrosion performance of CGM were studied under different concentrations of sulfate and chloride ions, steel slag contents and water/CGM (W/CGM) ratios. The flexural strength, compressive strength and corrosion resistance coefficient of CGM were measured in dependence of the days. Scanning electron microscopy (SEM) analysis was carried out to determine the anti-corrosion characteristic of CGM. The results showed that the corrosion resistance coefficients of CGM are generally larger than 1.0 under different sulfate and chloride ion concentrations. Steel slag prevents sulfate ions from penetrating the hardened stone body, and the anticorrosion performance of CGM was relatively low at high W/CGM ratios.

From the perspective of sustainable development and environmental protection, the environmental friendly substitute of ordinary grouting materials is needed to be proposed. In this paper, we prepared a high-performance and low-cost grouting materials from red mud, granulated blast furnace slag (GBFS) and class F fly ash (FFA). In order to determine the optimal raw materials property, we investigated the effect of FFA dosages on red mud–GBFS grouts system. The results showed that 10% of FFA content could improve the 90-day compressive strength of grouts by 15.4%; fluidity and volume stability were also improved considerably. But when the FFA content is overmuch, it would result in some negative effects, such as longer setting time and higher bleeding rate. According to the mineral phase analysis, the effects of FFA mainly attributed to the physical properties before 28 days, such as ball effect, filling effect and micro-aggregate effect, and the pozzolanic effect of FFA influenced the long-term performance chiefly. Above all the results in this study, the optimum dosage of FFA is 10%.

Leakage of lining structure is one of the main geological disasters of the tunnel, which brings heavy economic losses and casualties. Aiming at the problem of lining leakage of the Kaiyuan Tunnel in Jinan, this research has carried out a geological survey, conducted statistics, and classification of the leakage situation of the Kaiyuan Tunnel. The causes and main control factors of various types of seepage are analyzed. To locate the leakage accurately, electrical resistivity tomography, transient electromagnetic method, and ground penetrating radar are used to carry out comprehensive geophysical exploration. Two catchment zones and fractured zones are determined based on the existing geological topographic maps, geological profile maps, and geological analysis results. Transient electromagnetic detection results coincide with the known fractured zones, which confirms the existence of fractured zones and defines the scope of fractured zones. Moreover, the detection results based on ground penetrating radar show that the main adverse geological conditions inlining and surrounding rock are water diversion area, hidden water diversion area and surrounding rock fragmentation area. Subsequently, three kinds of grouting material, ultra-fine cement, ordinary Portland cement, and polymer cement, were selected for seepage control of the 800–900 m and 1310–1330 m test sections for plugging treatment. The grouting effect was analyzed and evaluated based on ground penetrating radar detection and field working conditions. Especially, the grouting radar detection shows that the grouting effect of polymer cement slurry is ideal, the grout in the water conduction area is basically filled, and the lining cracking and damage have been significantly repaired and improved. This paper verifies the accuracy and good feasibility of the interpretation criteria of comprehensive geophysical detection for typical lining defects, which can be popularized and applied in relevant tunnels and underground projects.

Tunnels in the operation period are faced with different types of diseases, such as lining fracture, lining containing voids and lining leakage. In this paper, the common tunnel lining diseases are classified and ground-penetrating radar (GPR) is adopted to detect the tunnel lining diseases rapidly and nondestructively. The finite-difference time-domain (FDTD) method is used to carry out numerical experiments on GPR detection forward modelling and backward projection imaging. An interpretation criterion of GPR detection was established on typical lining diseases. Based on the dielectric differences between before and after grouting of tunnel lining, GPR is introduced into the evaluation of grouting on leakage in tunnel lining, and the numerical simulation of grouting effect is carried out. It can be concluded that GPR imaging can well-identify the dielectric changes before and after grouting and evaluate the grouting reinforcement effect more intuitively. Finally, this method was applied to a practical case in Kaiyuan tunnel, China. This paper provides an alternative way to detect tunnel lining leakage in operation period and a reference for the evaluation of structural defects reinforcement in underground engineering.

To explore solutions for water plugging and reinforcement problems of water-rich and broken rock mass in underground engineering, it is necessary to study the performance of cement-based grout and its reinforcement effect. In this study, Portland cement-based grouts with high amounts (70%) of granulated blast-furnace slag (GBFS) (30%) and Class C fly ash (FA) (40%) were prepared. The superplasticizer (SP) and anti-washout agent (AWA) were formulated to improve flowability and stability of single slurries. A new self-developed experimental device was designed for the grouting simulation. The fresh-state properties of cementitious single slurry i.e., flowability, mini-slump, stability, effective W/S and initial/final setting time; flexural and compressive strengths of grout stone bodies were studied. Meanwhile, the grouting reinforcement effect; mechanical performance of reinforcement sample i.e., unconfined compressive strength (UCS), failure mode, process and key parameters were evaluated. The results show that the performance and grouting effects of cement-based grouts with high amounts of GBFS and FA were generally acceptable. The addition of SP + AWA enhanced the stability and was beneficial to the grouting effectiveness especially at higher (0.8–1.2) water-solid (W/S) ratios. The diffusion or setting time of this type grout should be shortened appropriately in practice. The rupture interface and tensile fracture of grout were two main failure modes of reinforcement samples. The variations of key parameters corresponding to different failure modes were analyzed.

Objective and scientific risk assessment is of great significance for tunnel construction. The intrinsic link between risk level and influencing factors are poorly understood, and our abili...

Ground penetrating radar is a popular approach to detect defects in tunnel lining. However, the interpretation is usually based on the original image, which is very different from the real shape of the lining defects. Full waveform inversion and reverse time migration are helpful to solve this problem. Full waveform inversion can invert the relative permittivity distribution and reverse time migration can migrate reflection events to their proper locations. Traditional full waveform inversion method is only applicable to cross‐hole ground penetrating radar data or surface multi‐offset ground penetrating radar data. We propose an improved full waveform inversion method which offers satisfactory inversion result for surface common‐offset radar. The forward modelled waveform and the objective function curve show that our new full waveform inversion method is much more accurate than traditional full waveform inversion for common‐offset radar. Traditional reverse time migration has weaker amplitude with increasing depth; we use an energy matrix to improve the imaging effect. Moreover, our reverse time migration is based on the relative permittivity distribution obtained from full waveform inversion, which provides more accurate imaging result. Through several numerical and engineering examples, we discuss the application of both methods in tunnel lining inspection. The results show that for tunnel lining without rebars, the combined methods can give satisfactory imaging results. But the image quality deteriorates rapidly when dealing with rebars.

Geological hazards such as water inrush often occur during tunnel excavation, which always cause economic loss and construction delay. Predicting the water-bearing structures ahead of tunnel face in advance would reduce these risks substantially. Electrical resistivity is considered as an effective technique to detect water-bearing bodies because of its sensitivity to low-resistivity body. However, abnormity of observed data caused by anomalous body below tunnel bottom or behind tunnel wall, called vicinal interference, is always more serious than that ahead of tunnel face. So the first problem is to design one observe configuration to prompt the sensitivity to the anomalous body ahead of tunnel face. A moving electrical-source method (MESM) is proposed in this study, in which source electrodes move along the survey line, and array of measure electrodes are fixed on the tunnel face. Numerical forward modeling examples show that the abnormality degree of MESM data caused by vicinal interference is much lower than that of a traditional observed mode. Electrical resistivity inversion method with inequality constraints is then presented to reduce non-uniqueness and instability. And prior information involving variation range of material resistivity, expressed as a mathematic constraint, is introduced into traditional resistivity inversion equation. Numerical inversion tests are carried out on several geological models and the imaging features, inversion quality and limitation are analyzed and summarized. The test results from both physical model and field experiments the water-bearing body prospecting utilizing MESM has acceptable error and satisfies the accuracy demand in geological ahead prospecting in tunnels.

Background. The aim of the present study was to investigate the association between fibrinogen-to-albumin ratio (FAR) with contrast-induced nephropathy (CIN) in patients undergoing emergency percutaneous coronary intervention (PCI). Methods. 565 patients with emergency PCI were consecutively enrolled. The primary outcome was CIN defined as either a 25% increase in baseline serum creatinine levels or a 0.5 mg/dL (44 μmol/L) increase in absolute serum creatinine levels within 72 h after the contrast medium exposure. Logistic regression analysis was applied to analyze whether FAR was an independent risk factor for CIN. Results. Overall, 29 (5.1%) patients developed CIN. Compared with the patients without CIN, the patients developing CIN had lower albumin (39.79 ± 3.95 vs. 37.14 ± 5.21, P=0.012) and higher fibrinogen levels (3.51 ± 0.94 vs. 4.14 ± 0.96, P<0.001). In the multivariate logistic analysis, FAR was an independent predictor of CIN (OR = 3.97; 95% CI, 1.61–9.80; P=0.003) along with perihypotension, age >75 years, and LVEF Conclusion. Preprocedural levels of FAR were associated with CIN in patients after emergency PCI.

Hydrological tracer testing is an effective way to determine the law of recharge and the transport of groundwater. In karst collapse mine water treatment, the hydrological tracing test can determine information such as the runoff velocity and the pattern of underground runoff, so that targeted grouting becomes possible. In this paper, NaCl was used as a tracer, and the content of the tracer was determined by the chloride ion selective electrode method. The NaCl concentration&ndash, time curve was plotted, and we obtained a tracer test method that can determine the runoff of the karst quantificationally. The method can quantificationally obtain the groundwater transport velocity, runoff pattern, and connectivity. This combination of grouting rate, grouting pressure, and setting time realized the localized targeted grouting and achieved a significant water damage control effect.

In order to address the environmental problems caused by red mud and other industrial by-products, a new concept was proposed to use red mud to prepare cementitious materials by incorporating other solid wastes, waste heat, and tail gas. The feasibility of this synergistic concept was verified by laboratory-scale tests, and the effect of tail gas and waste heat on solid wastes was revealed by FTIR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction), and SEM-EDS (Scanning electron microscopy-Energy Dispersive Spectroscopy), and the key device for carbonation disposal was developed. The results showed that the cementitious reactivity of industrial solid wastes can be improved by carbonation disposal of tail gas. The cementitious reactivity of Sintered red mud, coal gangue, fly ash, and Bayer red mud was increased by 49.8%, 4.4%, 9.5% and 18.9%, respectively. The multi-solid waste system with Bayer red mud, steel slag, carbide slag, aluminum ash, and flue gas desulfurization gypsum can generate high performance red mud-based cementitious materials (RCM) with a compressive strength of 8.8 MPa at 1 d under the circumstance of high temperature disposal. And RCM consists of 2CaO·SiO2, 3CaO·Al2O3, and CaO·(Al2O3 + Fe2O3). In addition, the mechanical strength and soundness of RCM can be improved by the carbonation of tail gas. This innovative concept provides a way for the mass utilization of red mud along with other solid wastes, waste heat and tail gas through the relevant cementitious materials for use in transportation construction, and shed light on the cleaner production of industry.

In karst areas, the water inflow in underground pipelines often shows the features of large and high flow rate that is extremely difficult to treat. Due to long hardening time, poor bonding of the interface and low retained rates during dynamic water filling, the ordinary inorganic grouting materials are easy to lead to sealing failure. Magnesium phosphate cement has the characteristics of good interfacial bond and quick solidification, which is very appropriate for karst piping sealing. In the study, a water-resistant scour grouting material based on potassium dihydrogen phosphate, light burnt magnesium oxide, metakaolin, sodium silicate, and bentonite is developed. This grouting material is a modification of potassium magnesium phosphate cement and some of the MgO and KH2PO4 is replaced by metakaolin (0–30%). Then, these three materials make up the gel material system. The fresh grouts designed water-binder ratio is 1 and the material is sodium silicate and (0–6%) modified with bentonite (10%). The properties of the grouting material including compressive strength and bending strength (after 1 day, 3 days, 7 days, 14 days, and 28 days), setting time, viscosity, and flow distance are studied. We used X-ray diffraction and scanning electron microscope to study the microscopic properties of a hardened grouts. Our experimental results show that the MgO/KH2PO4 (molar ratio), sodium silicate and metakaolin affect the compressive strength, bending strength, gel time, and viscosity of the grouting material. The addition of metakaolin reduces the early strength and the fluidity of the grouting materials, but the grout with 20% metakaolin has a higher 28-day strength. The sodium silicate reduces the setting time and rheological property of the grouting materials but increases their strength.

Grouting reinforcement technology plays an important role in the field of disaster prevention and control of deep underground engineering. Due to the insufficient workability and mechanical property of recycled cement (RC) under high water to solid ratio, there is still a blank about recycled cement used in grouting materials. In order to propose a new high-performance, low-cost environmental grouting materials and expand the application field of RC, this study examined the effect of phosphogypsum and flue gas desulfurization gypsum on the performance and microstructure of RC thermal activated with different temperatures, high purity natural gypsum and blank sample were designed as control group. Test results indicated that three kinds of gypsum all prolonged the initial setting times, and improved the fluidity and mechanical properties of RC grouts. Especially, 10% phosphogypsum added to the 750 °C thermal activated RC, optimal proportion of RC to gypsum system, can obtain a higher compressive strength (6.33 MPa for 3d and 11.26 MPa for 28d) than P.O.42.5 cement with 1.0 water to solid ratio, prolong the initial setting times from 5 min up to 27 min, which makes the RC capable of using as grouting materials. The microscopic analysis results showed that the increase in the compressive strength was attributed to gypsums can promote the generation process of C-S-H and ettringite in RC, the impurity of phosphogypsum also participate in the hydration process and generated crystalline substances such as calcium phosphate silicate.

Water inflow in a karst area has the characteristics of a large water volume and a fast flow rate, which makes the water inrush of a karst conduit flow extremely difficult to treat. Ordinary inorganic grouting materials have weak bonding with the interface, long initial and final setting time intervals and high loss rates of dynamic water filling. Phosphate cement has good interfacial bonding and instantaneous final setting after the initial setting, which is suitable for dynamic water conduit plugging. In this work, we developed anti-scouring grouts based on light-burned magnesia, potassium dihydrogen phosphate, Class F fly ash, water glass, and bentonite. A condensate based on potassium magnesium phosphate cement (MKPC) is formed using Class F fly ash (0–30%) to replace some of the MgO and KH2PO4. Then, the three materials form a cementitious material system. The water-cement ratio is 1:1 and is then modified with bentonite (5%) and water glass (0–6%). The basic properties of the grouts were studied by measuring the setting time, viscosity, compressive strength (after 3 d, 7 d, and 28 d), and flow distance. The microscopic properties of the hardened stone were studied by using both X-ray diffraction (XRD) and scanning electron microscope (SEM). The experiments show that the molar ratio of MgO to KH2PO4 (M/P) along with the water glass and fly ash contents play a significant role in the setting time, compressive strength, and viscosity of the grouts. The addition of fly ash can reduce the fluidity of the grouts and the early strength; however, the 28-day compressive strength of the grouting material mixed with 30% class F fly ash is higher than that of the grouting material mixed with 10% and 20% Class F fly ash. Water glass can reduce the setting time and fluidity of the grouts and can increase the strength of the grouts.

The aim of the study is to evaluate the association of pre-procedural N-terminal pro-B type natriuretic peptide (NT-proBNP) with contrast-induced acute kidney injury (CI-AKI) and long-term outcomes in elderly patients undergoing elective percutaneous coronary intervention (PCI).A total of 540 patients aged ≥ 75 years who had undergone elective PCI between January 2012 and December 2015 were enrolled in this study. Admission NT-proBNP levels were measured before PCI. CI-AKI was defined as a relative increase in serum creatinine (SCr) of ≥50%, or an absolute increase of ≥ 0.3 mg/dL, occurring within 48 hours after contrast medium exposure. The predictive value of NT-proBNP for predicting CI-AKI was assessed by receiver operating characteristic (ROC) and multivariable logistic regression analysis.A total of 54 (10.0%) patients developed CI-AKI. The best cutoff value of NT-pro-BNP for detecting CI-AKI was 1133 pg/mL with 66.7% sensitivity and 70.8% specificity according to the ROC analysis (C statistic = 0.719; 95% CI, 0.679-0.756). Multivariable analysis demonstrated that Lg-NT-proBNP is significantly related to CI-AKI (odds ratio [OR] = 3.892; 95% CI, 1.996-7.590; P < 0.001). Cox regression analysis showed that Lg-NT-proBNP is associated with long-term mortality (adjusted hazard ratio [HR] = 2.158; 95% CI, 1.246-3.740; P = 0.006) during follow-up.Pre-procedural NT-proBNP is a significant and independent predictor of CI-AKI and long-term mortality in elderly patients following elective PCI, and the best cutoff point for predicting CI-AKI was 1133 pg/mL.

Zhe-Bin You,1,* Kai-Yang Lin,2,* Wei-Ping Zheng,1 Chun-Jin Lin,1 Fan Lin,1 Tai-Lin Guo,1 Peng-Li Zhu,1 Yan-Song Guo2 1Department of Geriatric Medicine, Fujian Provincial Hospital, Fujian Key Laboratory of Geriatrics, Fujian Provincial Center for Geriatrics, Fujian Medical University, Fuzhou, People’s Republic of China; 2Department of Cardiology, Fujian Provincial Hospital, Fujian Cardiovascular Institute, Fujian Medical University, Fuzhou, People’s Republic of China *These authors contributed equally to this work Purpose: Inflammatory factors play a critical role in contrast-induced acute kidney injury (CI-AKI). Prealbumin, a nutritional and inflammatory indicator, is a well-established predictor of short- and long-term outcomes in numerous clinical conditions. The current study investigated the association of pre-procedural prealbumin levels with CI-AKI and long-term outcomes in geriatric patients after elective percutaneous coronary intervention (PCI).Patients and methods: A total of 558 patients aged≥75years, who underwent elective PCI between January 2012 and December 2015, were selected for the current study. Pre-procedural prealbumin levels were measured before PCI. Multivariable logistic regression and Cox proportional hazard regression analyses were performed to identify the independent risk factors for CI-AKI and long-term mortality.Results: Out of 558 patients, 54 developed CI-AKI. The optimal cutoff value of prealbumin for detecting CI-AKI was 185.5mg/L with 62.7% sensitivity and 70.4% specificity based on the receiver operating characteristic analysis (C-statistic=0.710; 95% confidence interval [CI] 0.673–0.751). Multivariable analysis demonstrated that prealbumin≤185.5mg/L was significantly associated with CI-AKI (odds ratio [OR] 0.397; 95% CI 0.195–0.808; P=0.011). Cox regression analysis demonstrated that prealbumin≤185.5mg/L was associated with long-term mortality (adjusted hazard ratio [HR] 0.525; 95% CI 0.289–0.952; P=0.034) during the follow-up.Conclusion: Pre-procedural levels of prealbumin were independently associated with an increased risk of CI-AKI and long-term mortality in elderly patients undergoing elective PCI. Keywords: prealbumin, contrast-induced acute kidney injury, percutaneous coronary intervention, elderly&nbsp

The convergence to the equilibrium of the solution of the quantum Kac model for Bose-Einstein identical particles is studied in this paper. Using the relative entropy method and a detailed analysis of the entropy production, the exponential decay rate is obtained under suitable assumptions.The theoretical results are further illustrated by numerical simulations.

Objective: Low free triiodothyronine (fT3) is common in elderly patients with cardiovascular disease. The purpose of this study was to evaluate the relationship between low fT3 and contrast-induced acute kidney injury (CI-AKI), including the long-term outcomes, in elderly patients after a percutaneous coronary intervention (PCI). Methods: A total of 350 patients aged ≥75 years who underwent PCI between January 2012 and December 2015 were consecutively enrolled. The perioperative thyroid function, including fT3, was measured before PCI. A low fT3 was defined as fT3

Water inrush disaster seriously affects the safety of karst tunnel construction. It’s essential to assess the risk level of water inrush in karst tunnels accurately, and take some effective countermeasures to reduce the damage to the project. We integrates the variable weight theory and cloud model theory to construct the VW&ICM calculation model to evaluate the risk of construction of karst tunnels. First, we select the index factors that affect the risk of water inrush from karst tunnels. Secondly, according to the theory of variable weight, we construct the zoning variable weight model, and the normalization criterion of the data from index factors is established. Thirdly, according to the attribute mathematic theory, we select the numerical characteristics of the improved cloud model, and the normal cloud generator is used to establish the point membership function. Finally, the risk index data is brought into the variable weight vector function and the point membership function to obtain the variable weight vector W and the membership degree matrix R. The risk overall evaluation vector B is further calculated, and the membership degree fluctuation is comprehensively analyzed according to the principle of maximum membership degree. The scope determines the risk of water inrush from karst tunnels. Finally, calculate the variable weight vector W and the membership matrix R, and the overall risk evaluation vector B is further integrated by W and R. According to the max-subjection principle and the fluctuation rule of membership, we get the risk level of water inrush in karst tunnel. The VM&ICM not only can quantitatively evaluate risk by considering the uncertainty of risk assessment and the influence of indicator size on weight, but also can make an analysis of the reliability to make the assessment result more convincing. The model makes improvement in weakening the influence of subjective factors on assessment results and in allocating the weight of indicators. A simple and practical software package is developed, which greatly improves the computational efficiency of VW&ICM method. The VW&ICM calculation model is applied to the risk assessment of water inrush for karst tunnels, and the results are basically consistent with the on-site construction situation.

During operation of the Kaiyuansi Tunnel, water leakage from the lining frequently occurs in the rainy season, seriously impacting the safety of the tunnel structure. To study the occurrence mechanism and evolution law of water leakage in operating tunnels passing through intersecting faults under different burial depths, both a large-scale 3D physical model test and numerical simulations were carried out. The results of the water leakage volume, vertical displacement and hydraulic pressure of the monitoring sections in the physical and numerical models were analyzed. The vertical displacement and hydraulic pressure of the model increase with increasing applied load and water pressure. Because of the higher water conductivity and lower strength of the intersecting faults, the influence of intersecting faults on tunnel water leakage is greater than that of surrounding rock. The intersecting faults have a very close hydraulic connection, and the main fault plays a major role in the seepage of groundwater. The results show that the internal defects of the lining material and quality defects of the tunnel construction are the main factors leading to water leakage in operating tunnels, and the uneven settlement of strata is another important factor in lining cracking and water leakage of operating tunnels. Finally, some useful suggestions and conclusions for tunnel construction and operation were obtained from the test results.

An interval risk assessment method of water inflow and inrush in karst tunnel is proposed. Based on the method, both a conceptual and a computational form of the risk assessment model is introduced, and risk surroundings, construction factors and feedback information are analyzed. The conceptual model consists of three hierarchies and three stages. Thirteen factors were chosen as assessment indices and can be grouped into three categories: karst hydrogeological conditions and geological engineering conditions, construction factors and feedback information for management. An analytic hierarchy process and fuzzy mathematical theory were used to develop a computational model based on the interval number. The interval membership function and the weight of each factor were quantified and a relative superiority analysis of the interval matrix was performed. Moreover, a construction permission mechanism of water inflow and inrush in karst tunnels was established. In the present study, the three-stage risk assessment model and construction permission mechanism were successfully applied to the Qiyueshan tunnel. Thus, the interval risk assessment method may provide a practical reference for the risk assessment and management of karst tunnel construction and is worth exploring to control risk in other engineering construction projects.

International audience; This paper is devoted to the analysis of the Cauchy problem for a system of PDEs arising in radiative hydrodynamics. This system, which comes from the so-called equilibrium diffusion regime, is a variant of the usual Euler equations, where the energy and pressure functionals are modified to take into account the effect of radiation and the energy balance containing a nonlinear diffusion term acting on the temperature. The problem is studied in the multi-dimensional framework. The authors identify the existence of a strictly convex entropy and a stability property of the system, and check that the Kawashima-Shizuta condition holds. Then, based on these structure properties, the well-posedness close to a constant state can be proved by using fine energy estimates. The asymptotic decay of the solutions are also investigated.

Introduction: D-dimer(DD) is associated acute renal injury, However, whether DD is an independent risk factor of contrast-induced acute kidney injury(CI-AKI) in patients undergoing primary percutan...

International audience; This paper is devoted to the analysis of global smooth solutions to the multidimensional isentropic Euler equations with sti relaxation. We show that the asymptotic behavior of the global smooth solution is governed by the porous media equation as the relaxation time tends to zero. The results are proved by combining some classical energy estimates with the so-called Shizuta-Kawashima condition.