33 results about "Blast load" patented technology

The invention provides a method for analyzing bench slope stability under blasting effect, and belongs to the technical field of open-pit mining. Compared with a conventional method, the method combines numerical simulation with vibration monitoring, and uses vibration information of a slop body to correct material parameters of the slop body, and provides more accurate input parameters for numerical simulation. A numerical simulation method coupling finite elements with discrete elements is used to perform mechanical analysis, and progressive failure process of the slope under blast load effect is completely depicted. A calculation result is more accurate. Rupture degree is used to evaluate slope stability, and internal damage and rupture conditions of a slope body can be directly reflected, and an evaluation index is more reasonable.

The invention discloses a rock blasting super dynamic strain field monitoring and analyzing system which can well obtain an experiment effect of a dynamic fracture mechanics experiment under the load of blasting the natural rock. The system comprises a loading unit, a high-speed high-resolution image pickup unit, a light source unit, a synchronization unit and a digital image analysis unit, wherein the loading unit is used for carrying out blast loading on a natural rock test block and generating a super dynamic strain field in the test block; the high-speed high-resolution image pickup unit is used for carrying out alternative shooting or simultaneous shooting on the dynamic fracture process of the natural rock test block by at least two digital imaging subunits so as to obtain crack propagation images at different moments; the light source unit is used for providing illumination or reinforcing illumination light for the natural rock test block; the synchronization unit is used for carrying out synchronous control on actions of the loading unit, the high-speed high-resolution image pickup unit and the light source unit; and the digital image analysis unit is used for analyzing images shot by the image pickup unit. The system is suitable for performing the dynamic fracture mechanics experiment under the load of blasting the natural rock.

The invention provides a rock and earth mass shear rheometer taking rainfall and blast vibration reciprocal actions into account. The rock and earth mass shear rheometer comprises a shear rheology unit, a dry-wet cycle unit, a blast disturbance unit and a CCD displacement automatic measurement system for detecting displacement of a lower shear box. The blast disturbance unit provides disturbance for the shear rheology unit through a rigid support and a vibration motor and simulates blast loads, and the rigid support is formed by a vertical supporting rod piece, an upper rigid rod piece and a lower rigid rod piece. The connecting positions of the vertical supporting rod piece and the upper rigid rod piece and the lower rigid rod piece are adjustable, and the disturbance transmitted to a pressurization system is adjusted to achieve disturbance loads of different strengths and quantitative simulation of blast loads in the rheological test process. According to the rock and earth mass shear rheometer taking the rainfall and blast vibration reciprocal actions into account, blast loads and rainfall reciprocal actions of different frequencies, strengths and periods can be effectively simulated in the shear rheological test process, and displacement change conditions of a sample in the test process are measured accurately to be used for quantitative research on shear rheological characteristics of rock and earth mass under the rainfall and blast vibration reciprocal actions.

The invention discloses a mechanical analysis model of adjacent buried pipeline under tunnel excavation and blasting load and a determination method of vibration velocity control standard. The mechanical analysis model includes pipe transverse and longitudinal mechanical model under tunnel excavation unloading and blasting disturbance. The vibration velocity control standard is determined by comparing the calculated value of mechanical analysis model with the theoretical value of pipe failure. The buried pipeline is regarded as the elastic ring in the elastic medium of the soil in the lateralmechanics analysis model of the pipeline under the influence of tunnel excavation and unloading. In the longitudinal mechanical analysis model of pipe under the influence of tunnel excavation and unloading, the pipe is regarded as a Winkler foundation beam supported on soil. The pipe under the influence of tunnel blasting disturbance is regarded as a viscoelastic foundation beam supported on soil.The theoretical value of pipeline failure is determined according to von Mises yield criterion. The invention realizes the quantitative analysis of the influence of tunnel excavation blasting on thepipeline, so that the material performance of the pipeline can be brought into full play and the construction progress of the tunnel is accelerated.

The invention discloses a horizontal well layer blast crack body modeling method based on unit elimination technology in a finite element analysis method; a plane stress-displacement relation equation and a maximum tension stress brittleness fracture quasi side equation in a linear elastic fracture mechanics theory are applied so as to build up a simulation horizontal well layer blast crack body mathematical model; the modeling method comprises the following steps: horizontal well shaft instantaneous blast load characteristic rule description; model application scope selection; initial crustal stress balance; far field boundary condition setting; unit type and size selection and determination; stress wave propagation damping influence in rocks. The mathematic model can use a blast impact module of an existing finite element calculating tool to solve, and solved value simulation result can vividly and directly reflect geometry form and geometry dimension of a crack body generated by horizontal well layer blast, thus providing objective theory basis for analyzing layer blast pressing crack effect influences by different parameters.

The invention discloses a surrounding rock damage range prediction method based on releasable elastic strain energy, and the method comprises the following steps: 1, building a circular tunnel blasting excavation analysis model, and obtaining a ground stress transient unloading and blasting load coupling action process; 2, calculating the surrounding rock strain energy change process under the coupling effect of ground stress transient unloading and blasting load; 3, introducing a damage coefficient xi, establishing a rock mass unit damage criterion based on releasable elastic strain energy; and establishing a relationship between the distance from the surrounding rock to the center of the excavation section and the dynamic fluctuation peak value of the surrounding rock strain energy, andsubstituting the fluctuation peak values of the surrounding rock strain energy at different surrounding rock radiuses and corresponding stress fields into a newly established damage criterion for judgment and calculation to complete prediction of the surrounding rock damage range. According to the surrounding rock damage range prediction method based on the releasable elastic strain energy, the problem that the accuracy is reduced due to the fact that the discreteness of the disturbance parameter D is very large when the disturbance parameter D is evaluated can be solved, and the prediction result is more accurate.

The invention discloses a method for calculating a load coefficient of a uniform cross-section and simply-supported beam comprising near-field blast and far-field blast. The method comprises the stepsof: firstly, establishing a uniform load model of a uniform cross-section and simply-supported beam under the action of near-field blast and far-field blast, and establishing a coordinate by taking the mid-span position of the uniform cross-section and simply-supported beam as the coordinate origin, the horizontal rightward parallel beam direction as the x axis direction and the direction vertical to the x axis direction as the y axis direction; and, selecting the mid-span cross section of the uniform cross-section and simply-supported beam as an observation position, wherein constraint conditions of two end parts of the uniform cross-section and simply-supported beam are same, solving a first-order vibration mode function by adopting Taylor's third-order substitution, selecting a typicalblast impact wave overpressure peak parameter value and an explosive equivalent, and thus, determining the blast load coefficient of the uniform cross-section and simply-supported beam comprising near-field blast and far-field blast. A uniform calculation formula obtained by the method can provide relatively accurate calculation numerical value for structural design calculation; and the design risk due to ignoring of the near-field blast in the traditional method can be reduced.

The invention discloses a multi-parameter blast vibration safety evaluation method. The method comprises the steps as follows: a blast vibration signal is decomposed into a series of simple harmonic loads with a wavelet packet decomposition and reconstruction method, energy of the simple harmonic loads is calculated and subjected to normalization processing, then dynamic response of a structural system is calculated under the action of the simple harmonic loads, meanwhile, the normalized energy is proportionally blended into vibration response of the structure, then criterion of blast vibration safety of the structure can be given according to a vibration response admissible value of the structure, and the safety of the structure is evaluated. The criterion is a safe multi-parameter blast vibration criterion capable of reflecting parameters such as the structural property, blast load amplitude, multiple dominant frequencies, duration, energy proportion and the like, and is more detailed, more reasonable and more scientific than the conventional blast vibration safety permissible criterion.

The invention provides a novel composite material for improving underwater antiknock performance of wading buildings. Based on high-strength reactive concrete, the novel composite material is characterized by being prepared through isometrically replacing a certain proportion of fine sand in the concrete by high-performance hollow glass microbeads in an equal volume and then carrying out mixing. According to the novel composite material, an appropriate quantity of high-performance hollow glass microbeads are mixed on the basis of high-strength reactive powder concrete, so that the obtained novel composite material has high compressive strength and strong anti-corrosion ability, and is resistant to direct impaction effects of blast loads caused by near-field underground contact and non-contact; and the high-performance hollow glass microbeads in the composite material can be used to clip and reflect shock waves, so that the novel composite material is capable of significantly improvingthe antiknock performance of the buildings, and is especially suitable for the underwater antiknock performance of the wading buildings.

The invention discloses a method for calculating a reasonable buried depth during construction of an undersea tunnel by a drilling and blasting method. The hydrogeological and engineering geological conditions of a construction site are considered comprehensively, the tunnel burial depth is calculated separately under the influence of the single factor of engineering analogy method, stability of surrounding rock, rock fracture damage, blasting loads and seismic loads, drainage design and cost and tunnel construction safety, hierarchical analysis of the importance of the factors is carried out,weight calculation of the influencing factors of the reasonable buried depth during the construction of the undersea tunnel by the drilling and blasting method is carried out by adopting a weight analysis method, and therefore, a reasonable buried depth value of the undersea tunnel constructed by the drilling and blasting method is obtained.

The invention discloses an experiment loading system and method for researching the movement crack interaction mechanism.A time-prolonging controller is utilized to send out trigger signals to control a multi-channel pulse ignitor, the multi-channel pulse ignitor detonates explosive in catheter cartridge bags after receiving the trigger signals, impact force generated by explosion of the explosive acts on an impact head, the impact head impacts a test piece under the action of the blast load, and the test piece is cracked and generates movement cracks.The time-prolonging controller can send out a plurality of trigger signals simultaneously or sequentially to control the multi-channel pulse ignitor to detonate multiple cartridge bags simultaneously or sequentially, and the test piece can generate two or more movement cracks simultaneously or sequentially.The experiment loading system can change positions where the movement cracks are generated in the test piece and the initial expansion direction of the cracks by changing the relative position of the impact head and the test piece, great flexibility is achieved, and different experiment requirements can be met.

The invention discloses a judgment method for dynamic responses of reinforced concrete columns under a blast load. The method comprises the following steps: (1) single macroscopic spring units without physical length are respectively built at two ends of the reinforced concrete columns, and comprise axial springs and shearing springs; (2) an area surrounded by stirrups in the cross sections of the reinforced concrete columns is delimited as a core concrete area; an area at the periphery of the core concrete area is a periphery concrete area; the core concrete area and the periphery concrete area are respectively calculated to obtain stress-strain relationship curves of the axial springs and the shearing springs; (3) an axial pressure-axial deformation relationship curve of the axial springs and a shearing force-shearing deformation relationship curve of the shearing springs are obtained to build a macroscopic model which is analyzed by the dynamic responses of the reinforced concrete columns under the blast load. The judgment method can accurately and timely judges the dynamic responses of the reinforced concrete columns under the blast load.

The invention provides a reduced-scale model design method of a high-rise RC frame structure. The reduced-scale model design method is used for predicting the far-field explosion damage effect of thehigh-rise RC frame structure; a high-rise RC frame structure similarity model under the action of a far-field blast load is established by adopting a similarity theory so as to judge the damage effectof the prototype; when destructive tests such as damage research of a high-rise RC frame structure under the action of a far-field blast load are carried out, the introduction of model tests can reduce the experiment cost, and the method has the advantages of easiness in development, high feasibility and the like.

The invention discloses a blast vibration response prediction method based on a spline interpolation. The method includes the steps: acquiring measured data of rock and soil medium vibration under theaction of a blast load; calculating proportion dosage of each measuring point, and performing waveform filtering on an acquired waveform of each measuring point; performing fast Fourier transform onmeasured time domain waveforms to obtain waveform frequency domain amplitude spectrums and phase spectrums; extracting frequency domain amplitudes and phase values of the waveform frequency domain amplitude spectrums and phase spectrums at all time; performing spline interpolation on a frequency domain amplitude and a phase value corresponding to a waveform of each frequency component at each measuring point thrice to obtain a fitted curve; substituting the proportion dosage of the measuring point into the fitted curve to obtain frequency domain amplitudes and phase values under frequency, andacquiring prediction frequency domain amplitude spectrums and phase spectrums by the aid of linear interpolation; acquiring time domain vibration prediction waveforms. According to the method, integrated blast vibration time histories of any position within a certain range can be predicted, prediction data needing to prepared is easily acquired, and practical engineering application is facilitated.

The invention discloses a crustal stress prediction method based on actually measured vibration. The crustal stress prediction method comprises the following steps: 1, obtaining a crustal stress transient unloading and blasting load coupling action process; 2, simulating the vibration response of the surrounding rock under different crustal stress levels when the crustal stress transient unloadingand the blasting load are coupled and when the blasting load is singly acted; 3, solving the difference value between the vibration peak value caused by the coupling effect of the ground stress transient unloading and the blasting load and the vibration peak value independently caused by the blasting load; establishing the relationship between the percentage of the difference value in the vibration peak value caused by the blasting load and the ground stress; and according to the actually measured vibration data, predicting the magnitude of the ground stress of the on-site excavation construction tunnel section by combining the relationship between the percentage of the difference value of the two load vibration peak values in the vibration peak values caused by the blasting load and themagnitude of the ground stress, so as to finish the prediction of the magnitude of the ground stress based on the actually measured vibration. According to the crustal stress prediction method based on the actually measured vibration, the problems that the precision is not high and the inclined stratum is not considered can be solved, and the prediction result is more accurate.

The invention discloses a treatment construction method for continuous collapse and roof fall in a small-section steep slope tunnel. The treatment construction method comprises the following steps that A, a plurality of rows of supporting arch frames are arranged; B, loose dangerous rocks after blasting load disturbance are blocked through a single beam structure supporting system and an integralarch structure supporting system formed by arranging barrier layers, supporting layers and protection layer pipe sheds, the downward sliding impact force is weakened, and a plurality of layers of buffer protection layers are formed; C, the limitation on a limited space of the small-section steep slope tunnel is overcome through a self-feeding drill pipe capable of being lengthened through assemblyand a conical drill bit with a spiral rotary steel ring, and the rotary drilling force and the rock crushing and breaking effect of the drill pipe are improved; and D, isolation waterproof layers arearranged at the tops of the supporting arch frames to weaken the soaking and softening effects of underground water, and the electric safety of construction in the tunnel is guaranteed. The treatmentconstruction method has the effects of high efficiency, quickness, safety and reliability for the treatment of continuous collapse and roof fall geological disasters in the small-section steep slopetunnel, the normal proceeding of tunnel blasting excavation is guaranteed, and the construction period is accelerated.