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Numerical simulation of geotechnical engineering requires mechanical data such as elastic modules, Poisson's ratio, cohesion and internal friction angle. Therefore, the identification of these parameters is crucial. This article deals with a novel intelligent identification method to determine the parameters of geotechnical engineering, which is a combination of genetic programming, genetic algorithm and FLAC3D. Besides, a case study of the Guzhi district of Tangshan city, Hebei Province, northern of China is offered .The equivalent rock mass parameters are accurately obtained, a numerical simulation is conducted with these parameters, whose results indicate that calculated displacements show good agreement with the measured displacements. Therefore, the method proposed in this paper is feasible to do the parameters estimation in geotechnical engineering.

A series of metal oxide supported tungstophosphoric acid catalysts were prepared by impregnation. The physicochemical and acidic properties of these materials were characterized by a variety of different analytical and spectroscopic techniques, namely Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) method, and nuclear magnetic resonance (NMR), and exploited as heterogeneous catalysts for selective oxidation of benzyl alcohol (BzOH) with hydrogen peroxide (H2O2). Among them, 20 wt.% H3PW12O40/CeO2 catalyst exhibited the best oxidative activity. Further process optimization by response surface methodology (RSM) based on the Box-Behnken design model resulted in a benzyl alcohol conversion of 95.2% and a benzaldehyde yield of 94.2% with 98.9% selectivity, in good agreement with the experimental results. Kinetic studies based on an irreversible parallel reaction model led to an activation energy (Ea) of 44.73 kJ mol-1.

A series of organic-inorganic composite catalysts were prepared by modifying tungstophosphoric acid (H3PW12O40) and propyl sulfonic acid-functionalized ionic complex. The obtained water-soluble catalysts were well characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and nuclear magnetic resonance, and investigated for their performance as homogeneous catalysts for selective oxidation of benzyl alcohol (BzOH) with hydrogen peroxide (H2O2) in water. Among them, the [DMBPSH]H2PW12O40 catalyst exhibited the best oxidative activity with a desirable benzaldehyde (BzH) selectivity of 97.0% and an excellent BzOH conversion of 98.5%. Further kinetic studies and model analysis by response surface methodology revealed that alcohols’ oxidation reaction followed an apparent order of 2.2 with an activation energy of 36.18 kJ/mol. And the optimal reaction conditions were established as follows: BzOH/H2O2 molar ratio of 1:1.7, amount of catalyst 5.4 wt%, reaction time 3.9 h, amount of water 24 ml, and a maximum yield of BzH of 95.8%. Under optimum conditions, [DMBPSH]H2PW12O40 catalyst showed a superior catalytic efficiency and reusability due to strong acidity and excellent surface activity.

Studying the parameters of fuel explosion fireball is an important measure for hazardousness assessment. In this paper, traditional methods are summarized and a new method of fireball characterization by which the heat released from detonation agent and liquid fuel could be distinguished is presented. In this method, the explosion processes, explosion properties and explosion damage are studied by capturing the high speed images and thermal images of explosion fireball. Among them, the analysis of explosion properties is the most important part, including fireball size, spreading rate of fireball diameter, surface temperature and radiation intensity of fireball. The hazardousness of liquid fuel field explosion could be evaluated through both single-parameter and multi-parameters combined in this method. Four examples are selected to indicate the effectiveness of this method.

This paper addresses the basic concept of fire and explosion suppression technologies for light petroleum fuel, proposes two research directions in fire-resistant fuel and explosion-suppression material technologies, and reviews the main research progress on these two fields home and abroad. It focuses on the research on fire-resistant diesel and non-metal spherical explosion-suppression material. The fire-resistant and self-extinguishing properties of the fire-resistant diesel is proved by micro-structure analysis, sustainable combustion performance test and welding test with fuel tank. Meanwhile the performance of non-metal spherical explosion-suppression material is verified by horizontal shock tube test and 30 mm Fragmentation Explosive Incendiary Shells (FEIS) bombing test, exhibiting its outstanding explosion-suppression performance, especially in the suppression of secondary-explosion process of the fuel gas.

Taking horizontal shock tube as the main equipment in this paper, using chemical ignition and high voltage ignition as the ignition source to evaluate the flame wave propagation characteristics of spherical nonmetallic explosion-suppression materials and aluminium alloy explosion-suppression materials when the horizontal shock tube was filled with No. 93 gasoline and liquefied petroleum gas vapors. The trend of peak overpressure and the flame propagation speed was tested, and the mechanism of flame and overpressure propagation was analyzed in the experiment. The results show that the spherical nonmetallic materials are better than aluminium alloy explosion-suppression materials for peak overpressure and flame wave propagation velocity suppression.

The microstructure and size distribution of water-in-oil (W/O) particles of micro-emulsified diesel (MED) with different cosurfactants were measured by High Resolution Transmission Electron Microscopy (HRTEM) and Nano-Laser Particle Size Analyzer (NLPSA). The combustion and explosion performance of MED with different cosurfactants were measured by the sustainable combustion performance testing device and explosion performance testing device for liquid fuel. The results show that the average particle size of MED which uses octanol as cosurfactant is smallest as 16.1 nm and has good size distribution uniformity. Flash point of MED is slightly higher only when using octanol as it's cosurfactant. The fire resistant abilities order of different MED is that octanol > decanol > hexanol > pentanol >n-heptanol. Comparing with - No.-10 diesel, the maximum explosion pressure and pressure rise rate after MED decreased by 0.09 MPa and 1.34 MPa/s, respectively.

Jet fuel is a kind of hazardous chemical and it can easily result in combustion or explosion accidents in the process of production, use, storage, transportation and other aspects, so its safety issues are essential and urgent. Explosion performance testing device and combustion performance testing device have been used to study the combustion and explosion characteristics of high flash point jet fuel and No.3 jet fuel. The results show that the explosion pressure and explosion pressure rise rate have a rising trend with the spray pressure increases. The ignition time of high flash point jet fuel was later than that of No.3 jet fuel, showing that high flash point jet fuel is more safety than No.3 jet fuel. The obtained combustion and explosion parameters of the two kinds of jet fuel from the experiments can be used to evaluate their safety quantitatively.

In this paper, three kinds of explosion-suppression materials including aluminum alloy, polyurethane foam and spherical polymer are measured to get the data of displacement ratio and retention ratio, which can be used to calculate the reduction ratio of effective volume of the oil tank. The results show that the displacement ratio of the three kinds of materials are respectively 2.0%, 2.5% and 5.2%, the retention ratio are respectively 1.1%, 3.2% and 0.4% and the reduction ratio of effective volume are respectively 3.1%, 5.7% and 5.6%. Meanwhile, the cook-off properties of the oil tank filled with spherical high molecular explosion-suppression materials were tested, the methanol in the tank didn’t explode, and materials in the tank didn’t deform and be destroyed during the experiments. All of the results showed that the spherical high molecular explosion-suppression materials presented a good explosion-suppression performance.

To assess the flame retardant and explosion suppression performances of fire resistant diesel fuel, static experiments with ordinary diesel fuel (Diesel fuel 1, D1 for short) and fire resistant diesel fuel (Diesel fuel 2, D2 for short) detonated by explosives were performed in this study. The explosion process and surface temperature of the fireballs were recorded using a high-speed camera and an infrared thermal imager. Meanwhile, the overpressures of the explosion shock waves of the two diesels were also recorded using pressure sensors embedded in the ground. The experimental results show that the diesel fuels are dispersed and ignited to produce explosion fireball when explosive is detonated in fuel tank. At the same time, part of diesel fuel produces pool fire on the ground. The pool fire of D1 lasts about 3000 ms, while D2 lasting only about 700 ms. The maximum temperature and the duration of high temperature of D1 explosion fireball are 1558.8°C and 1392 ms respectively, which are 1.11 and 1.29 times those of D2. In the position of 2 m far from the vertical projection point of the explosion center, the overpressure of the explosion shock wave of D1 is 53.30 kPa, while that of D2 is 31.60 kPa. Moreover, the overpressures of D1 are also higher in the other location of the pressure area. Therefore, it is proved that the explosive power of D2 is significantly lower than that of D1, and the flame retardant and explosion suppression performances of D2 is better than those of D1.

Considering potential explosion hazard of oil and gas pipeline, the technological solutions have been proposed, within certain transportation distance to fill non-metallic explosion suppression material with good chemical stability and high pressure resistance to prevent flame and explosion wave propagation in pipeline. Detonated in the high voltage ignition and chemical ignition head two types of gasoline vapor explosion conditions, spherical explosion suppression material filling stop explosion pressure propagation and realize the explosion suppression function. The results of horizontal shock tube experiment shows that there are obvious laws of blasting pressure increase drop before and after filling explosion suppression materials. The transport resistance form 150 mm diameter steel pipeline filled with explosion suppression material has also been investigated in different length and different air velocity conditions. The experimental results show that filling spherical explosion suppression material have had a limited effect in transportation capacity of pipeline.