The amplification of blasting vibration on rock slopes significantly impacts the accuracy of vibration monitoring and slope safety evaluation. This study investigates the phenomenon through numerical simulation and explores the amplification mechanism based on structural dynamics and vibration mode analysis. The simulation results show that the vibration amplification phenomenon primarily occurs in the vicinity of the bench crest. Influenced by the geometric dimensions of the bench crest and the physical and mechanical parameters of the rock mass, higher peak vibration velocities occur at the bench crest than at the bench toe, due to an increase in platform width, a decrease in bench height, a reduction in the slope ratio and a lower rock mass quality. Conversely, the distribution of the first principal stress exhibits an opposite trend to that of the peak vibration velocity. To improve the accuracy of safety assessments, it is recommended that monitoring points be placed at the bottom line of the bench. The vibration mode analysis further confirms that the amplification effect is predominantly governed by the low-order vibration modes, determined by geometric dimensions and mechanical parameters of the rock mass. The agreement between the mode analysis and numerical simulation results highlights the critical role of low-order vibration modes in controlling the slope's vibration amplification.

The matching relationship between explosives and rocks is crucial for improving the energy utilization efficiency of explosives, enhancing blasting effectiveness, and reducing costs. Firstly, this study analyzed the energy distribution during drilling and blasting operations. Then, the damage zone calculation model was revised considering the non-ideal detonation characteristics of explosives and the strain rate effect on rocks. And an on-site mixed explosives and rock matching model was then developed based on the control of energy transmission efficiency. Finally, field experiments were conducted to verify the rationality of the new explosive-rock matching method. The results show that the new method is more scientific and reasonable than traditional methods, and can intuitively reflect the blasting fragmentation effect and energy utilization efficiency, by taking account of the non-ideal detonation behavior of mixed explosives and the strain rate effects on rock damage partition. Blasting fragmentation tests under various explosive-rock matching conditions revealed discrepancies with the traditional wave impedance theory. By applying the new explosive-rock matching method, the percentage of fines was significantly reduced, and the boulder yield decreased from 6.7% to below 1%, further validating the method's effectiveness.

Efficient coordination between different processes is crucial in optimizing resource allocation and minimizing energy consumption during blasting operations in open-pit mines. To address these challenges, the theory of blasting sharing control is proposed, which integrates macroscopic ore fragmentation with mesoscopic damage analysis and introduces a novel ore damage model for the shoveling process. By optimizing inter-process connections and considering factors such as wear and depreciation, a comprehensive energy distribution model is developed across drilling, crushing, blasting, shoveling, and transportation processes. Evaluation and control indices are proposed for each process, leading to the establishment of a blasting sharing control model. The results demonstrate that the ore damage model reveals the multi-phase characteristics of rock blasting failure and effectively predicts the crushing energy consumption by regulating fragmentation levels. With a fitting accuracy exceeding 0.8, this model optimizes the crusher operations while reducing energy consumption. Using the blasting sharing control model enables calculation of the optimal solutions for blast parameter design while establishing an optimal comprehensive energy consumption formula under the constraint conditions, thus enabling the accurate adjustment of energy at each link and providing strong support for efficient, safe, and sustainable mine operations.

To investigate the impact of a radially uncoupled charge structure on energy transfer and blasting effects of explosives, with the goal of improving energy efficiency and enhancing rock crushing, dinitrodiazophenol was placed in a standard shale specimen with a diameter of 50 mm and a height of 100 mm. A blasting model experiment was conducted using four radial uncoupled charge coefficients -1, 1.5, 2 and 2.5. The strain waveforms in the axial direction of the specimen were analyzed using the ultra-dynamic strain testing system and the complementary set empirical mode decomposition method. The strain behavior of different sections of the specimen was studied, along with the damage fractal dimension and crack development in these sections. The analysis of the explosive energy propagation laws, combined with the strain curve, revealed that the tensile strain peak values were generally higher than the compressive strain peak values. The specimen eventually failed after experiencing significant and repeated tensile and compressive stresses. Importantly, when the radial uncoupling coefficient was 1.5, the energy utilization of the explosive was significantly improved, along with the prolonged action time of the detonating gas. Additionally, the damage fractal dimension of the specimen section with an uncoupled charge structure changed from top to bottom in an “n-type” manner, resulting in the most uniform damage distribution across each section, a fully expanded crack area, and the best blasting effect.

In order to study the energy evolution and fracture characteristics of sandwich composite rocks under impact loads, six sets of sandwich composite rock specimens were created using three materials: sandstone, marble, and granite. Dynamic fracture impact tests were then conducted using the Hopkinson pressure bar system to analyze crack propagation morphology, stress wave waveform characteristics, crack tip stress field, and energy loss relationship. The DLSM simulation results were also used to analyze the propagation law of stress waves and the evolution process of kinetic energy during dynamic fracture processes. The results showed a good fit between the dynamic fracture process captured by high-speed cameras and the crack propagation process simulated by DLSM. It was observed that the occurrence of cracks depends on the failure of weak bedding planes. Under the same impact conditions, the lower the strength of the weak bedding planes, the shorter and more advanced the crack propagation time, and the more energy is used for crack propagation. Additionally, under the same incident energy conditions, using a specimen with higher hardness as the impact end material results in a stronger reflection effect, greater reflection energy, weaker transmission effect, smaller transmission energy, and greater energy dissipation of the specimen. The bedding plane was found to have a significant hindering effect on the propagation of stress waves.

In order to investigate the mechanical properties and energy transfer law of jointed deep tuff under one-dimensional dynamic loading, seven kinds of tuff specimens with specified natural joint inclinations were tested by SHPB test device. During the tests, the dynamic process was recorded by high-speed camera in real time. The influence of joint inclination angle on the dynamic response characteristics of deep tuffs was systematically analyzed in terms of dynamic strength, energy dissipation and macroscopic damage. The results show that tuffs has the lowest dynamic strength when the joint inclination is 45°, and the dynamic compressive strength and peak strain show a tendency of decreasing firstly and then increasing in the range of joint inclination angle increasing from 0° to 90°. Besides, the final damage modes of the specimens are controlled by the nodal inclination, and the final damage modes of tuff specimens with different nodal inclinations can be classified into tensile damage, tensile-shear composite damage and shear damage. When the incident energy is roughly the same, the reflection energy ratio and transmission energy ratio of tuff present a decrease-increase trend with the increase of natural joint inclination angle, with the lowest energy ratio at 45°. However, the trend of the dissipation energy ratio is opposite. The energy-time density increased first and then decreased with the increase of joint inclination angle. When the direction of load and joint is within 45°~60°, more energy is absorbed and used for self-crack propagation.

To solve the problem of the filling bodies failure on both sides of the room caused by differential blasting of large diameter deep holes in underground mine, the stress field generated by differential blasting should be studied to determine a reasonable edge hole spacing and a delay time between the holes. According to the stress wave propagation and attenuation law, the front and rear detonation hole distance, delay time, and edge hole distance generated by complex stress field were determined. Furthermore, the superposition of the stress wave generated by the two-hole differential blasting in the blasted rock mass and the filling body was analyzed according to the wave theory. The stress field function analytical formula of the two-hole differential blasting was obtained. Meanwhile, the collapse range of the blasted rock mass and the failure range of the filled body under different side hole spacing conditions under the same hole spacing and delay time were determined. The LS-DYNA numerical simulation software established six numerical models, and the stress critical points were selected in the blasted rock mass and filling body for analysis after simulating the initiation of explosives under different schemes. The simulation results show that different edge hole distances had almost no effect on the collapse range of the exposed rock mass when the distance between edge holes was more significant than the range of the crack zone. Appropriately increasing the distance between edge holes can effectively reduce the damage caused by stress waves to the filling body. Finally, the field industrial test of four groups of blasting parameters was carried out, and the optimized blasting parameters were determined as the spacing between the two holes on the same side was 2.0 m, the delay time between the front and rear initiation holes was 9 ms, and the side hole spacing was 1.8 m.

Rock's mechanical parameters and fragmentation characteristics significantly change under the freezing and thawing environment in high-altitude cold regions, and it is difficult to directly apply traditional blasting parameters for excavation. Therefore, researching blasting design parameters in freeze-thaw environments is of great importance. This study analyzed the impact of freeze-thaw cycles on rock mechanical properties and conducted the crater experiments of single-hole and double-hole simultaneous blasts in ore rocks under freeze-thaw conditions based on Jurong Copper mine. Futhermore, the geometric parameters and block size distribution of the crater were measured after blasting, and the reasonable parameters for blasting design were determined using the mathematical fitting methods. Additionally, the changes in the blasting crater parameters of the mine were also compared and analyzed under four different rock conditions. The results show that the mechanical properties of rock mass significantly deteriorate with a decrease in uniaxial compressive strength and elastic modulus of up to 40.6% and 54.0% under freeze-thaw cycles, respectively. The optimal burial depth ratio for single-hole blasting of freeze-thaw ore rocks is 0.678~0.789 under different lithological conditions, and the ratio of the optimal charge burial depth to crater radius is distributed in the range of 0.875~1.076. For Chibula mining area, the hole diameter is 152 mm, the diorite hole net parameter is 4.5 m×3 m, the corresponding explosives consumption is 0.56 kg/m3, and the tuff hole net parameter is 5 m× 4 m with a 0.63 kg/m3 explosives consumption. For Jurong mining area, the hole diameter is 310 mm, the tuff blasting hole net parameter and explosive consumption is respectively 7 m×5 m and 0.61 kg/m3, and the granite porphyry hole net parameter and explosive consumption is respectively 8 m×5 m and 0.64 kg/m3.

The high-pressure equation of state is the basis of studying the failure mechanism of materials and the propagation law of shock waves under explosion or impact loading. The state of rock has a wide range of applications in the numerical calculation of mining, meteorite impact cratering, rock impact protection, etc. Using a two-stage light gas gun and Photon Doppler Velocimeter (PDV), the Hugoniot relationship, high-pressure equation of state and volume strain equation of red sandstone were studied. The lowest and the highest impact pressure generated by the collision were 7.2 GPa and 19.4 GPa, respectively, and the lowest and the highest planar impact velocity were 0.88 km/s and 1.97 km/s, respectively. At the same time, optic probes were used to measure the shock wave velocity of rock samples. However, The Hugoniot-Elastic-Limit (HEL) point of the red sandstone was not found in the free surface velocity profile recorded by the PDV, indicating that the red sandstone was in a near-fluid state within this impact pressure range. Furthermore, the shock wave velocity D and particle velocity u were linearly fit by the least square method, and the Hugoniot parameters of the red sandstone were C0=3.04 and =1.14, respectively. In addition, the relationship between the volumetric strain and the impact pressure P were obtained by polynomial fitting, which was P=116-7452+18453, and the nonlinear fitting coefficient was 0.993. The Hugoniot equation of state and bulk strain equation of red sandstone obtained in this work can provide reference data for numerical calculation and engineering application in red sandstone rock blasting, shock protection engineering, and so on.

With the gradual increase of mining depth, the engineering geological conditions of deep broken surrounding rock mass become complex and changeable, greatly affecting underground projects' construction process and subsequent use period's safety. In order to ensure the safety and quality of deep broken soft rock roadway during the construction process, advanced roof control reinforcement and controlled blasting technology for soft rock roadway were put forward. In view of the characteristics of highly developed fissures and poor stability of rock mass at the No.6 intersection of -550 m level in Zhongjiu iron mine, it was proposed to adopt advanced roof control measures to strengthen the surrounding rock mass of the roof and improve the bearing capacity of deep-buried broken soft rock roadway. In order to facilitate the excavation construction, 17 excavation areas were divided along the northeast side of the No.6 intersection, and a four-step method was used for segmented construction. To realize the hole-by-hole shot and reduce the influence of blasting vibration, the detonation interval between two adjacent digital electronic detonators was randomly set to 3~5 ms. According to the overall lithology of different excavation areas, the support methods (pipe shed support, W-shaped steel belt, anchor cable support, etc.) were optimized to ensure the safety of the subsequent use of the No.6 intersection. The test results show that the advanced roof control reinforcement and controlled partition blasting technology can reduce the roof deflection and subsidence of broken soft rock roadway, which ensures the forming effect of the No.6 intersection section and reduces the cost of support and shotcrete by 8.7%.

For large cross-section tunnel blasting, the rock mass in the middle of the tunnel face often experiences the phenomenon of “bulging” due to the unreasonable arrangement of the cutting holes. In order to eliminate the “bulge belly” phenomenon in large cross-section tunnel blasting, a new method of “wedge cut+high-energy hole” blast hole layout was proposed. Taking the Gonghe Village Tunnel of the Luqiao Expressway in Yunnan Province as the engineering background, a numerical model of “wedge-shaped cut+high-energy hole” was established using finite element software LS-DYNA. The effective stress at the bottom of the blast hole and dynamic damage of the rock mass were studied and compared with the on-site tunnel cut blasting plan. At the same time, the proposed new method was verified through on-site blasting experiments. The research results indicate that the “wedge cut+high-energy hole” blasting hole layout method can effectively eliminate the “bulge” phenomenon, reduce the number of cut holes and digital electronic detonators, and determine the rationality and applicability of this method. Besides, the stress values generated by measuring points 1, 2, and 3 at the bottom of the main cutting hole are relatively small. As the stress sharply rises to 454.9 MPa, the middle-retained rock mass can be effectively broken after the main cutting hole blasted with the high-energy hole explodes. Using the improved blasting method, the excavation efficiency increased by 16.9%, the average utilization rate of blast holes reached 91.5%, and the explosive consumption reduced by 19.7%. The proposed layout method of “wedge-shaped cutting+high-energy holes” for large cross-section tunnels can not only ensure construction safety, but also achieve the effect of reducing costs and improving construction efficiency.

To reduce the loss and dilution of ore in Husab Mine, a blasting movement monitoring (BMM) system was introduced and tested in three production blocks with 177 mm diameter drilling holes and a 7.5 m step height. During the field test, 6, 8, and 5 monitoring holes were arranged in each test block. Two displacement monitoring balls were placed in each monitoring hole at a 3.5 m and 9m depth to record the rock body's vertical and horizontal movement after blasting. The results show that the movement of the ore body due to blasting can be detected by BMM, and the average horizontal displacement of the upper ore body of the three test blocks is 6.55 m, 6.97 m, and 9.24 m, respectively. The average horizontal displacement of the lower ore body is 3.2 m, 3.9 m, and 4.0 m, respectively. The average vertical displacement of the upper ore body is 4.1 m, 2.0 m, and 3.2 m, respectively. The average vertical displacement of the bottom ore body is 0.72 m, 0.98 m, and 0.84 m, respectively. The ore body always moves in the direction with the least resistance during blasting. Whether horizontal or vertical displacement, the displacement of the upper ore body is always more significant than that of the lower ore body. In addition to changes in the boundaries between the ore and rock due to horizontal displacement, vertical displacement also has a significant influence on the loss and dilution of ore, and the bottom ore body may also move to the middle or the upper part of the ore body, and vice versa. The blast zone of open pit mines often consists of a variety of rocks, and both horizontal and vertical displacements of the ore body after completing the blast design based on geological information are the leading causes of ore grade reduction. Using the post-blast rock boundaries obtained from the BMM system monitoring to guide the excavation and transportation operations, the average ore dilution rate has been reduced by 1.2%. The average loss rate has been reduced by 1.5%, which can create more than 10 million RMB of economic benefits cumulatively over the entire life of the Husab Uranium Mine. This technology can accurately define the ore-rock boundary after blasts, which is an important technical means to reduce the ore dilution rate, ore loss rate and ore grade classification errors in open pit mines.

As tunnels are integral to railways and other transport infrastructures, studying the vibration response and attenuation rule of tunnel blasting for tunnel construction projects is significant. The blasting solutions proposed in this paper are to minimize clear distance in the blasting excavation of a high-speed railway tunnel for the Chongqing-Kunming high-speed railway construction project. A new excavation method was developed to divide the excavation section into alternating blasting on both the left and right sides. Besides, the blasting vibration velocity of the double-line tunnel was monitored. The vibration velocity analysis of the advance tunnel shows that the maximum vibration velocity in the tunnel is mainly caused by cutting hole and vault auxiliary hole blasting, and the radial vibration velocity is the maximum. The vibration velocity of the arch waist of the explosion side wall is 1.3 to 2 times bigger than that of the arch foot on the cross-section, and the ratio caused by the initiation of the cutting hole is relatively small. Meanwhile, the vibration velocity of each point in front of the tunnel face is more significant than that at the relative position behind the vertical section. In contrast, the attenuation rate of the vibration velocity behind is relatively more significant. The research findings have been successfully applied to the engineering practice, and a relevant small clear distance tunnel has been safely connected.

To study the continuous collapse resistance and dynamic response characteristics of the structure after the blasting failure of the local columns of the RC frame building, the deformation and stress adjustment process of the beam-column substructures adjacent to the columns were observed in real-time through an on-site blasting test of the central column of a blasting and demolition project of an 8-storey frame building. The PKPM was used to establish the corresponding building model. Meanwhile, the dynamic response characteristics of the remaining structure under the failure of the central column and the resistance to continuous collapse was calculated by the demolition component method and the demolition component method in SAP 2000. The results show that the theoretical value of strain after the blast failure of the center column is about 260 using the strain-moment theoretical formula. The dynamic strain measured in the field is about 377 , and the value calculated by the numerical simulation is about 238 . The results of the dynamic strain by the three methods are relatively close. The computed value of the vertical displacement at the failure point is 3.2 mm, close to the field displacement of 2.67 mm, and the calculated value of the plastic angle is 0.051°, close to the field angle of 0.05°. The remaining structure experienced a significant dynamic impact at the instant of the central column failure, and the acceleration values along the positive and negative directions are roughly the same, with a maximum value of 3.5 m/s. After the failure of the central column, the load redistribution occurs in the remaining structure, and the vertical load originally borne by the central column is shared by the surrounding columns, resulting in a significant catenary effect on the upper beam body.

To control the height and recoil distance of a frame-shear wall structure after demolition by blasting, a frame-shear wall residential building demolition project in Qingdao was chosen as the subject. The simulation analysis used ANSYS/LS-DYNA software and the orthogonal combination of collapse angle and crotch extension time difference. Firstly, a finite element model of the original scheme was built, and the model's validity was checked by comparing the variance between the model prediction and actual outcomes. Then, the trends of the structure recoil distance and burst pile height with the change were analyzed by changing simply the model's inter-span extension time difference and cut height. Furthermore, the semi-quantitative formulas for the relationships between recoil distance and burst height with notch height and inter-span delay time difference were proposed based on the outcomes of multi-scenario numerical simulation, which were allowed for the determination of the inter-span delay time difference and notch height for the cases of minimum structural recoil distance and burst height, respectively. Finally, the analysis was carried out on the acceptable span-to-span extension time difference and the range of blasting notch heights for demolition blasting of frame-shear wall structures. The results show four fundamental steps to the collapse of frame-shear wall structures: blast notch creation, destabilized overturning, notch closure, and landing collapse. The study's findings indicate that the recoil distance of each model primarily increases at first and then decreases as the inter-span extension of the blast section is prolonged at the same cut height. Meanwhile, there is a more significant disparity in the structure's recoil distance as the deferred time difference is extended, and the recoil distance increases with the height of the blast cut at the same inter-span extension. Additionally, the height of the detonation pile roughly decreases as the time lag increases. The shear walls simultaneously improve the structural integrity and prevent the building from collapsing during the collapse, resulting in better structural integrity after collapse. The structure reduces recoil distance when employing a short incision height and a 200 ms extension time difference. The most minor burst heights of the structures are those with considerable notch heights and a 300 ms delay time difference. A crotch delay time difference of between 270 and 420 milliseconds is adequate. More importantly, a large blast cut can lower the pile's height, while a tiny blast cut can effectively regulate the recoil. It can be reasonably chosen based on the demands of the area around the structure that will be torn down. The study can provide a guide for determining the incision height and delay time difference for demolishing frame-shear wall structures by blasting.

The multi-body and discrete-body dynamic analysis of demolished reinforced concrete structures in China is based on the multi-body dynamic equation (symbol, function) and the variable mass collapse dynamic equation, and the comprehensive solution of the equation, including an analytical solution, is obtained. Using close-range photogrammetry and dynamic equation inversion, the plastic dynamic and structural dismantling parameters of damaged reinforced concrete materials are obtained. Based on the similarity criterion of dynamic equations solution, similarity criterion formulas of notch for different collapse modes of Various structures are established. Namely, the similarity criterion curve fitting formula (5), it's another formula (6), empirical formula (7) of single-notch for building toppling, the example modification curve C4 of similarity criterion of inter-span falling, and the forward. Toppling similarity criterion formula (8) of backward-seated buildings with the single notch, the similarity criterion formula (9) of continuous impact collapse between floors of high-rise buildings, the empirical formula (10) of multi-notch in-situ impact collapse of high-rise buildings, the overturning similarity criterion curve of double-notch buildings in the same direction, and other notch-similarity criterion curve families of building structure collapse, etc. Furthermore, the building collapse rules of the demolition matching table of building structure-collapse mode-notch characteristics are put forward by analogy with 46 demolition examples from its notch similarity criterion curve and example diagram in China. The judgment rules of building collapse are determined when the coordinate points [（1,p）,h (r)] of the building structure and the incision are near the top of the similarity criterion curve. The cut size of various demolition methods of different building structures can be easily determined, and dimensionless charts can determine the demolition effects. Therefore, a simple and accurate demolition control of blasting demolition can be realized using the multi-body dynamic incision control demolition technology (MBDC).

Dynamic mechanical tests were carried out on EPS concrete at early ages (12 h、24 h and 36 h). Whereafter, the influences of impact velocity (4.5~6.5 m/s) and age (12 h、24 h and 36 h) on impact resistance of EPS concrete were analyzed in terms of dynamic compressive strength, peak strain, ultimate strain and energy dissipation density. Additionally, the properties of EPS concrete at early ages were compared with that at the age of 28 d. The results show that the dynamic compressive strength, peak strain, ultimate strain, and energy dissipation density of EPS concrete have an impact on the velocity-strengthening effect. With the increase of age, the dynamic mechanical property indicators of EPS concrete and its sensitivity to impact velocity increase. At the age of 28 d, the dynamic compressive strength, peak strain, ultimate strain and dissipation density of EPS concrete are the maximum, and its sensitivity to impact velocity is the strongest. EPS concrete has good deformation and energy absorption characteristics at the early age. At the age of 36 h, the peak strain, ultimate strain and energy dissipation density of EPS concrete can reach 66%~82%, 91%~93% and 72%~78% of that at the age of 28 d, respectively.

In view of larger holes and higher density operators with the traditional blasting of packed explosives, this paper launched 60 on-site blasting experiments in a plateau tunnel. The charging efficiency of different numbers of exploders was summarized, the hole network parameters were optimized and smooth blasting effect of peripheral holes were improved. Compared with the smooth blasting effect, the number of holes dropped from 151 to 124. The spacing of peripheral holes was gradually optimized from 45 cm to 60 cm based on the advantages of good mechanical and coupling charging on-site mixed explosives. The result shows that the on-site mixed loading blasting in plateau tunnel can improve more than 40% efficiency per operator and reduce 90% of labor intensity compared with the traditional blasting of packed explosives. It can significantly reduce the number of operators and improve the efficiency of drilling and loading, saving more than 15% of drilling quantity and explosive equipment. Lastly, more than 3% of the utilization of circular footage has been improved, which shows that on-site mixed-loading blasting can accelerate construction progress.

When conducting blasting under deep water, the explosive will be affected by high water pressure and long-term water immersion conditions due to the long charging time. Only when the performance of the explosive meets the technical requirements can the blasting effect be guaranteed. Taking the waterway regulation project of Liantuo river between the Three Gorges Dam and Gezhouba Dam as the research background, it was found the original emulsion explosives composition was weak in resisting deep water pressure during the reef blasting. The detonation distance was small, and the intensity was insufficient during the construction at a depth of 40 m. The performance of water gel explosives, chemical-sensitized explosives, glass microsphere-sensitized explosives, and perlite-sensitized explosives were studied by experiments in the laboratory adjusted the hydrostatic surface pressure to simulate the deep-water condition by using the deep-water measurement method. A relationship between the explosive performance and immersion time was explored under different water depth conditions. Meanwhile, a relationship between the explosive performance and water depth was built under different immersion time conditions. Comparing the experimental results, the study shows that the performance of glass microsphere-sensitized explosives, chemical-sensitized explosives, perlite-sensitized explosives, and water gel explosives all slightly decrease and meet the engineering requirements when the water depth is 0~20 m. It is recommended to use glass microsphere-sensitized explosives and perlite-sensitized explosives when the water depth is 20~40 m, and the glass microsphere-sensitized explosives are suitable when the water depth is 40~50 m. Besides, the glass microsphere-sensitized explosives have relatively small performance degradation under high pressure and long-term immersion conditions, and it is suitable for underwater drilling and blasting construction in deep water conditions.

Field tests in a region of the plateau were carried out to study the “poly device+emulsion explosives” in tunnel surface blasting and to achieve the feasibility of peripheral hole air spacing charge and poly device on the explosives detonation distance. A seamless steel tube was used to simulate the tunnel peripheral hole for two or more sections of “emulsion explosives+poly device” detonation. A martyrdom test was implemented with # 2 rock emulsion explosives. The maximum stable detonation and martyrdom distance were obtained through several groups of experiments. The test results show that the maximum stable detonation and martyrdom distance 15 cm length of polymerized explosives and # 2 rock emulsion explosives are respectively 230 cm and 115 cm in the seamless steel tube. The maximum stable detonation distance of multi-section polymerized explosives can reach 80 cm. Due to the radial constraints on the detonation wave of the polymerization device, the front end of the conical metal drug mask explosion formed by the polymerization of energy jets significantly increases the axial and upward shockwave energy, which makes it possible to increase the energy of the shockwave. The emulsion explosives in seamless steel pipe detonation distance increased significantly upward shock wave energy, which can be applied to the tunnel perimeter hole, replacing the detonating cord to achieve air spacing charge and enhance the effect of surface blasting, cost savings, and time savings.

To study the effect of aluminum powder particle size on the performance of CO2 phase change explosion exciters, the changes in the thermal decomposition characteristics, safety, temperature resistance, and reaction heat were investigated by the calorimetric method (TG), ignition test, temperature resistance test, and reaction heat test. The results show that the thermal decomposition characteristics of the excitation agent did not change significantly after adding 40、80 and 120 m aluminum powders. However, the apparent activation energy of the activator was significantly different. The apparent activation energy of the excitation agent containing 40 m aluminum powder decreased by 52.92 kJ/mol. Still, the apparent activation energy of the excitation agent containing 80 m and 120 m aluminum powders increased by 55.21 and 57.53 kJ/mol, respectively. After adding different particle sizes of aluminum powder, each sample can be ignited in the air, and the combustion process is accompanied by white smoke. Among them, the excitation agent with 120m aluminum powder burns more violently than that without aluminum powder and that with 40 and 80m aluminum powder. The experimental results show that the excitation agents containing different particle sizes of aluminum powder can be excited by the electric primer, but the sample is not completely ignited. When these excitation agents are in a closed environment and under a certain pressure (greater than or equal to 0.2 MPa), they can be reliably ignited without an obvious explosion phenomenon, indicating that their safety is good. After holding at 70 ℃ for 48 h, the overall excitation agent added with aluminum powder did not change significantly, and the temperature index Ts was about 70 ℃, indicating that its temperature resistance was good. When the mass percentage of aluminum powder with different particle sizes is the same, the increase in reaction heat is about 12%, indicating that the particle size has little effect on the reaction heat of the excitation agents.

Rock drilling and blasting inevitably produce blasting vibration effects and hazards. The accurate analysis and prediction of blasting vibrations and effective active control methods are thus of great practical significance. This paper summarises the achievements in the prediction and active control of blast vibration velocities over the past 40 years. In terms of predicting the peak value of the blasting vibration velocity (PPV), empirical model prediction methods are very convenient, but their prediction accuracy and effectiveness are poor. By introducing probability and statistical theory into empirical model prediction methods, the accuracy of PPV predictions can be improved. The fundamental wave superposition prediction method can comprehensively predict the vibration velocity, frequency, and duration. However, this method requires high testing accuracy for fundamental vibration waves, which requires the establishment of a regular calibration and verification mechanism for blasting vibration data acquisition devices in the blasting industry. Artificial intelligence prediction methods can significantly improve the accuracy of PPV predictions and provide new ideas for predicting blasting vibration effects under the influence of multiple factors. However, these methods are all based on massive amounts of real and effective measured data, and a substantial database of vibration testing data samples is currently lacking. Theoretical PPV prediction models and numerical simulation prediction methods have also been proposed. However, the widespread application of these methods in engineering practice is limited owing to the requirements for professional knowledge and numerical simulation technology. In terms of the active control of blasting vibration velocity, reasonable delay time determination methods for reducing the PPV are first discussed based on the superposition interference effect of vibration waveforms. However, the recommended delay time values proposed by most current methods are only suitable for protecting a single target structure. Then, a method for actively changing the delay time to regulate the frequency components of blasting vibration is discussed from the perspective of adjusting the spectral structure of blasting vibration, which can avoid the natural vibration frequency band and reduce blast vibration hazards to buildings (structures). However, this method currently remains at the theoretical level or under model experimental-scale conditions and lacks large-scale on-site application examples for verification. Finally, several key future research directions for the prediction and control of blasting vibrations are discussed.

To accurately predict the peak particle velocity (PPV) and effectively reduce the hazards of blasting vibration, a prediction model was built by BP neural network based on the blasting project of Xingguang No.1 open-pit mine. Seven influencing factors as core distance, plugging length, minimum resistance line, explosives unit consumption, maximum single-hole charge, total extension time, and maximum single-delay charge, were selected as input variables, and the correlation between each factor and PPV was evaluated by using the grey correlation analysis method. The Sparrow Search Algorithm (SSA) optimized the BP neural network to predict the three-way peak vibration velocity. By comparing and analyzing the prediction results of the BP neural network model, the average errors of the prediction results of the SSA-BP neural network model were 6.08%, 7.34%, and 1.91%, respectively, and that of the prediction results of the BP neural network model was 22.19%,54.01%, and 25.29%, respectively. The results show that the SSA-BP neural network model comprehensively considers the influence of multiple blasting design parameters on the peak vibration velocity. The sparrow search optimization algorithm can effectively solve the problem of the traditional BP neural network model, which quickly falls into the local optimum. The prediction results are more accurate, and the vibration velocity monitoring value is more consistent with smaller errors. Meanwhile, it can significantly shorten the learning and training time of the sample data to speed up the convergence speed of BP. Additionally, it can also significantly shorten the training time of sample data and accelerate the convergence speed of the BP neural network prediction model.

The blasting dynamic response of the gas pipeline and surrounding soil during the excavation of the cross passage at the entrance and exit C of Jinding Street Station of Beijing Metro Line 11 was analyzed using the finite software LS-DYNA. The numerical model's accuracy was confirmed by comparing it with blast-induced vibration data from on-site surveys. The study focused on the dynamic response of the buried gas pipeline to tunnel blasting, considering factors such as different cutting hole delay times, single hole charge, and soil properties. The results indicated that the peak particle velocity (PPV) from the numerical model was within 20% of the field test data. The PPV and peak effective stress (PES) of the pipeline were highest at the side back of the explosion source. A linear relationship between PPV values of the surface soil and the pipeline was observed when the horizontal distance from the tunnel center exceeded 3m in the axial direction of the gas pipeline. The PPVs and PESs on the cross-section of the gas pipeline did not change significantly with increasing delay times between cutting holes. Furthermore, increasing the charge of the cutting hole from 0.2 kg to 0.6 kg led to an increase of 0.5~2.5 times in PPVs and 0.5~1.5 times in PESs. The soil type around the gas pipeline also influenced the peak combined vibration velocity and effective stress, with silty clay having the greatest impact, followed by clayey silt, and then miscellaneous soil.

Although the rock stratum can be blasted into blocks in advance on the ground when the shield machine bores through silt-rock strata, the vibrations generated by blasting in silt-rock strata will threaten the safety of the water supply pipeline near the blast area. Based on the blasting vibrations of field tests and numerical simulations, the physical and mechanical parameters of the materials on sites were verified, and the dynamic response of the water supply pipeline near the blast area was studied. The research results show that the peak particle velocity (PPV) decreases with the increase of the horizontal distance from the explosion source on the pipeline along the axial direction. The PPV also decreases with the increase of the horizontal distance from the explosion source on the ground surface above the pipeline along the axial direction, and there is a relationship between the PPVs of the pipeline and the PPVs of the ground surface above the pipeline. The maximum PPV of the pipeline's inner wall is 3.97 times the minimum PPV, and the PPV is the highest at 90° of the inner wall. Meanwhile, the maximum PPV of the pipeline's outer wall is 1.03 times the minimum PPV, and the PPV is the highest at 150° of the outer wall. Besides, the PPV of each node is different from that of the other, and the PPV on the pipeline's inner wall is more significant than that on the pipeline's outer wall. Although the PPV on the pipeline's inner wall changes significantly, the PPV on the pipeline's outer wall is relatively close. The maximum peak effective stress of the element is 4.06 times the minimum peak effective stress of the element, and the peak effective stress of the element is the highest at 240°~270° of the pipeline's outer wall.

Porous sandwich structures are widely used in anti-explosion due to their excellent specific strength and stiffness. However, current explosion research mainly focuses on the failure mechanism of sandwich structures under small equivalent explosion loading. In contrast, the research on energy absorption characteristics of porous sandwich structures under actual large equivalent loading is rarely reported. To better guide the engineering application, ten kinds of sandwich structures with three kinds of sandwich materials (foam aluminum and honeycomb aluminum with 3 mm×10 mm side length) under different sandwich configurations (single-layer and two-layer sandwiches) and different thicknesses of face sheet/middle sheet/rear sheet were designed. The explosion tests with 0.5 kg TNT and 1 kg TNT equivalent explosion loading were respectively carried out on the above sandwich structures, and the overall deformation characteristics of the sandwich structures were analyzed. The effects of sandwich materials, sandwich configurations and other factors on energy absorption were discussed. Results show that both the foam sandwich structure and honeycomb sandwich structure could absorb energy through the large compression deformation of core material under explosion loading, while the deformation uniformity of the honeycomb structures is better. Furthermore, the energy absorption efficiency of the core is both related to its specific compressive strength and strength/stiffness of the face sheet/rear sheet. It is quite necessary to optimize those parameters to ensure that the core material can obtain a maximum compression and give full play to its energy absorption advantage. It is also found that the double-layer sandwich structure is superior to the single-layer sandwich structure on energy absorption and protection performance, which is an effective way to improve the overall energy absorption of the structure.

Husab Uranium Mine is a super-large-scale open-pit uranium mine. Currently, the mine adopts a “one-time design, long-term use” approach to blasting production, leading to issues such as a lack of dynamic adjustment of blasting parameters, high explosive consumption, and unsatisfactory blasting results. To address these issues, a solution can be achieved through dynamic blastability classification management of blasting blocks and feedback-controlled blast design. This study utilizes the production history big data of the mine's blasting blocks. It proposes a method to calculate the blasting index K using drilling rate (), explosive consumption per unit volume (), and fragmentation index (). Here, represents the drill hole cross-sectional area per unit area, where a higher value indicates more drilling required and higher drilling costs. represents the amount of explosives required per unit volume of crushed rock, where a higher value implies a more significant amount of explosives required and higher blasting costs. represents the distribution of fragment size after ore blasting, where a higher value indicates worse blasting effects, higher transportation costs, and greater difficulty in blasting. Based on the value of the blasting index K, the blastability of historical blasting blocks is classified into different levels. Uniaxial compressive strength (UCS) of the blasting blocks, rock quality designation (RQD) of the ore, and geological strength index (GSI) of the ore deposit are used as blastability indicators, establishing a dataset correlating blastability indicators with blastability levels. The dataset consists of 69 sets of historical data, with 20 sets classified as level one (easily blastable), 24 sets as level two (relatively difficult to blast), and 25 sets as level three (difficult to blast). Subsequently, a deep learning neural network model is constructed, comprising an input layer, five hidden layers, a dropout layer, and an output layer. The model is trained using blastability indicators as inputs and blastability levels as outputs. The traditional SVM model is used for comparison, revealing that the trained deep learning neural network model achieves higher prediction accuracy on the test set than the traditional SVM model. Finally, the reliability and accuracy of the trained deep learning neural network model in predicting the blastability level of blasting blocks are verified through on-site experiments, optimizing the blast design and blasting effects. The research findings indicate that the trained deep learning neural network model, based on a large amount of historical production data from Husab Uranium Mine, can be used for blastability classification of blasting blocks and optimization of blasting effects.

Blasting Engineering is an essential core course for civil engineering and mining majors. To improve the students' understanding on dynamic mechanical response and damage mechanism of rock materials, the experimental teaching contents of explosion and impact dynamics of rock materials were set up in a training plan to achieve the teaching goal of the course of Blasting Engineering. In view of students' lack of theoretical knowledge and experimental basis of impact dynamics in blasting engineering, the split Hopkinson pressure bar (SHPB) experiment technology and two-dimensional plate blasting (TDPB) experiment technology were applied to the practical teaching of Blasting Engineering. Firstly, the experimental system compositions and calculation principles of SHPB and TDPB were introduced. Secondly, the course contents of SHPB impact compression experiment and TDPB central blasting experiment of rock materials were designed. Thirdly, the dynamic mechanical behavior and energy evolution characteristics of sandstone material under the SHPB experiment and the strain wave evolution and dynamic damage and fracture behavior mechanism of sandstone-like material under the TDPB experiment were analyzed. Finally, the students' in-depth discussion on the critical problems of rock impact dynamics was guided. The innovative combination of SEM testing technology and impact dynamics experimental technology revealed the damage mechanism of rock materials under SHPB and TDPB experiments to students from the micro-level, which gave the students a clear understanding of meso-damage and macro-failure. The effect of teaching practice shows that the student's theoretical and practical ability is exercised by combining the experimental course of SHPB and TDPB with the theoretical course of Blasting Engineering, which leads to the improvement of students' scientific research ability and the sense of teamwork, and the fulfillment of the teaching goals.