CN-121977405-A - Calculation method of optimal ultra-deep coefficient in cut blasting based on ultra-deep blasting theory

CN121977405ACN 121977405 ACN121977405 ACN 121977405ACN-121977405-A

Abstract

The invention discloses a calculation method of an optimal ultra-deep coefficient in the ultra-deep cut blasting based on an ultra-deep cut blasting technology field, which comprises the steps of analyzing a mechanical balance relation in the movement process of rock fragments in a blasting groove cavity, deducing a relation between hole depth and the ultra-deep coefficient according to the theory, verifying optimal ultra-deep values under different hole depths through a contrast test, quantifying the required hole depth and the ultra-deep coefficient of a blasthole, calculating dynamic resistance in the groove cavity after the blasted rock mass is crushed, setting the reference of the ultra-deep coefficient in the limit balance state of crushing and throwing by theory, and quantitatively analyzing blasting hazard effects by using the rock crushing block and circulating footage after the blasting to measure the effect of the blasting scheme, so that the blasthole depth is accurately calculated through calculation of the ultra-deep coefficient for blasting under various complex environments.

Inventors

Chen Zhihuo
HUO XIAOFENG
TAO YI
LOU XIAOMING
CHEN BIGANG
XIE YELONG
HU YAN
LIAO DAGANG

Assignees

福建省交通科研院有限公司
福州大学
中昌核工(福建)建设发展有限公司

Dates

Publication Date: 20260505
Application Date: 20251211

Claims (2)

1. The method for calculating the optimal ultra-deep coefficient in the cut blasting based on the ultra-deep blasting theory is characterized by comprising the following steps of: Step 1, based on an ultra-deep blasting theory, analyzing a mechanical balance relation in a rock fragment movement process in a blasting groove cavity to obtain a relation formula: In the formula, And (3) with Are normal stresses on the face; Is the cohesive force of the rock; Is the internal friction of the rock; The distance between the cut hole and the empty hole is set; Is the auxiliary hole depth; the resistance of the rock wall in the blasting groove cavity to the corresponding surface of the blasting direction is shown; Step2, simplifying dynamic resistance balance relation in the process of moving rocks in the groove cavity; calculating other forces of the various portions within the undercut hole: the calculation formula of the auxiliary slitting cavity friction force is as follows: In the formula, The total mass of the fragments in the explosion area of the auxiliary hole and the explosive gas is mixed; The friction factor between the rock and the wall surface; The throwing speed of the rock fragments after blasting; The calculation of the friction force of the hollow cavity of the cut hole is as follows: In the formula, The total mass of the broken pieces in the cut area and the explosive gas are mixed; The total power calculation formula is: In the formula, Initial pressure for explosive gas; Is the volume ratio of the fragments; The volume ratio of the fragments is the instantaneous volume ratio after explosion; is the charge length; Is the radius of the charge; Is an ultra-deep coefficient; Step 3, calculating the total resistance of each blasting surface of the central slitting zone The formula is as follows: the calculation of the total clamping force of the cut section is In the formula (I), in the formula (II), For the clamping force of the hole bottom, Is the cross-sectional area; Finally obtaining the resultant force of the blasting throwing direction And 4, analyzing the relation between the rock fragment dynamic resistance and the clamping force, determining the relation between the ultra-deep coefficient and the hole depth, and deducing the optimal ultra-deep coefficient eta value, wherein the specific formula is as follows: Furthermore, under the support of the optimal ultra-deep coefficient eta value, the corresponding optimal ultra-deep coefficient eta values of different hole depths L can be obtained through calculation through various parameters of a construction site.
2. The method for calculating the optimal ultra-deep coefficient in the undercut blasting based on the ultra-deep blasting theory according to claim 1, wherein the method is characterized in that rock samples of a blasting site are obtained, physical mechanical parameters such as rock density, friction coefficient, longitudinal wave speed and the like are measured through an indoor rock mechanical test, and the ranges of various multi-source parameters of the ultra-deep blasting theory in the step 4 are obtained, wherein the following parameters are constants; Basic parameters of the explosive are obtained by adopting emulsion explosive and calculating the explosion speed Density of explosive ; Is an adiabatic coefficient, and generally takes a value of 3; Is the radius of the charge; The radius of the blast hole; The velocity of the explosive gas is increased by times, and the value is generally 8 to 11; For transmitting into the borehole wall an initial pressure is calculated by the following calculation formula: calculating the initial pressure of the wall of the gun hole as The full-coupling charging is adopted for charging, and the diameter of the cut hole is 40mm. Density averaging of blasted rock mass And velocity of longitudinal wave propagation in rock mass Uniaxial compressive strength of rock mass Ultimate breaking strength of rock mass under blasting action 。

Description

Calculation method of optimal ultra-deep coefficient in cut blasting based on ultra-deep blasting theory Technical Field The invention relates to the technical field of ultra-deep cut blasting, in particular to a calculation method of an optimal ultra-deep coefficient in cut blasting based on an ultra-deep blasting theory. Background Blasting is widely used in the foundation construction fields of municipal administration, water conservancy, traffic, underground space, open-air underground mining and the like. In the process of tunnel and tunnel tunneling, the cutting blasting technology affects the blasting effect to a great extent and simultaneously affects the tunneling efficiency. In actual construction, as the blast hole tunneling section of blasting only has one free surface, the rock clamp is large in manufacturing, the blasting operation condition is poor, and in the existing construction process, a shallow-hole inclined-hole cutting blasting process is mostly adopted, so that the single-cycle footage of the rock tunnel is lower, and meanwhile, the rock tunnel is influenced by factors such as the amount of excavated earth and stone, geological conditions, the physical and mechanical properties of rock, groundwater environment and the like. In the design of excavation and blasting, the explosion theory is not in conformity with the engineering practice, especially, each blasting surface in the blast hole is valued by the engineers according to the long-term accumulated professional experience, the blasting parameters are planned, and other related parameter designs of the cut blasting are determined. The design construction of the cut blasting is safely and effectively carried out, the focus is on accurately determining the blasting rock breaking range, determining the cut parameters, and simultaneously determining the proper delay time to improve the utilization rate of the blast hole, wherein the design is carried out on the fixed barrel-shaped cut blasting of the blast hole, the optimal ultra-deep coefficient is required to be calculated and obtained, the depth of the blast hole corresponding to the obtained different ultra-deep coefficients can be obtained under different geological conditions, the current mode of judging the depth of the blast hole only by experience is adopted, the ultra-deep coefficient is not taken as a consideration factor, and the depth of the blast hole is judged by experience of people, so that the standard is not available and cannot be taken as an accurate reference factor. Based on the above, the invention designs a calculation method of the optimal ultra-deep coefficient in the cut blasting based on the ultra-deep blasting theory, so as to solve the problems. Disclosure of Invention The invention aims to provide a calculation method of an optimal ultra-deep coefficient in cut blasting based on an ultra-deep blasting theory, by using the calculation method, the required hole digging depth and the ultra-deep coefficient of a blasthole can be quantified, firstly, the dynamic resistance of a groove cavity after the broken rock mass is broken can be calculated, and the ultra-deep coefficient is set and referenced in a limit balance state of breaking and throwing by theoretical calculation. The invention discloses a calculation method of an optimal ultra-deep coefficient in cut blasting based on an ultra-deep blasting theory, which comprises the following steps: Step 1, based on an ultra-deep blasting theory, analyzing a mechanical balance relation in a rock fragment movement process in a blasting groove cavity to obtain a relation formula: In the formula, And (3) withAre normal stresses on the face; Is the cohesive force of the rock; Is the internal friction of the rock; The distance between the cut hole and the empty hole is set; Is the auxiliary hole depth; the resistance of the rock wall in the blasting groove cavity to the corresponding surface of the blasting direction is shown; Step2, simplifying dynamic resistance balance relation in the process of moving rocks in the groove cavity; calculating other forces of the various portions within the undercut hole: the calculation formula of the auxiliary slitting cavity friction force is as follows: In the formula, The total mass of the fragments in the explosion area of the auxiliary hole and the explosive gas is mixed; The friction factor between the rock and the wall surface; The throwing speed of the rock fragments after blasting; The calculation of the friction force of the hollow cavity of the cut hole is as follows: In the formula, The total mass of the broken pieces in the cut area and the explosive gas are mixed; The total power calculation formula is: In the formula, Initial pressure for explosive gas; Is the volume ratio of the fragments; The volume ratio of the fragments is the instantaneous volume ratio after explosion; is the charge length; Is the radius of the charge; Is an ultra-deep coefficient; St