RU2139490C1 - Method for blasting near guarded objects - Google Patents

Abstract

FIELD: mining art, construction, applicable in blast mining (ground, concrete, etc) near guarded objects - buildings, constructions, mechanisms, pit edges, etc). SUBSTANCE: the earthquake - safe quantity (number) of holes and simultaneously (short-delayed inclusive) blasted charges at a blast depends on the parameters of the charge and arrangement of charge holes in the volume to be destructed, which makes it possible to combine the process engineering and norm quality of the blast with its earthquake-safety. The method comprises the marking of location of the rows of holes within the section of the rocks to be blasted, drilling of holes, their charging with explosive, mounting of blast network and blasting of charges in holes with a short delay; the area of the blast section is marked out and drilled according to a double-axis pattern of holes with the lengths of the sections of the pattern axial lines between their intersection equal to:

Description

 The invention relates to the field of mining, construction and can be used in the explosive development of the environment (soil, concrete, etc.) near the protected objects (OO) - buildings, structures, mechanisms, sides of the recesses, etc.

 There is a known method of blasting near guarded objects, including drilling rows of wells with a convergence coefficient of unity, charging them, dividing the array into symmetrical parts, connecting charges to the blast network and blasting charges with delay (see. Normative guide on drilling and blasting operations. -M .: Nedra, 1986, pp. 30-79).

 The disadvantage of this method is the low efficiency of providing a given set of technological requirements for explosive development and the lack of the possibility of matching the technology with the requirements of seismic safety.

 Closest to the claimed is a method of blasting near guarded objects, including marking the location of the rows of wells within the blast block, drilling wells, loading BB, installing an explosive network and blasting charges in wells shortly (see BN Kutuzov. Blasting operations .-M .: Nedra, 1988, S. 232-238).

 In this method, to obtain the desired results of the explosion (the crushing intensity, the power of the blasted layer and its working on the sole, the collapse of the blasted mass, etc.), drilling, loading and blasting of explosives (BB) with parameters (well diameter, step between charges , charge length and mass, etc.) according to the technological requirements and conditions for the explosion, as well as the physicomechanical properties of the developed array.

 However, the prototype method does not allow minimizing the number of wells and charges, it is agreed to provide both the specified quality of the explosion results and the required volumes of the array under development for seismic safety for nearby protected objects: production (technological) parameters of the explosion and seismic safety are implemented separately, so the first ones are not defined relative second, and the restrictions imposed by the requirements of seismic safety irrespective of technology either lead to a deterioration of the technology conditions while ensuring the design dimensions of the block being developed (for example, a decrease in the quality of crushing and working out of the sole due to an increase in the step between charges to reduce the total mass BB), or to reduce the developed volume with the necessary repeated blasting, or even to prohibit the use of an explosion by seismic hazard factor.

 The technical result of the invention is the production of simultaneously technologically rational and seismic safe explosions in the vicinity of guarded objects with an increased volume of blasting mass and a reduced number of charging wells, which is achieved by the fact that the seismic safe number (number) of wells and one-act (including short-delayed) blasting charges are set during the explosion depending on the parameters of the charge and the location of the charging wells in the destructible volume, which allows combining manufacturability and but Regulatory quality of an explosion with its seismic safety.

где S - обуриваемая площадь разрабатываемого участка, м², заряды в скважинах группируют в ряды и монтируют взрывную сеть так, чтобы в каждой i-ой серии короткозамедленного взрывания число зарядов равнялось

где

расчетное число зарядов, сейсмобезопасное (без учета эффекта их рассредоточения по площади) на расстоянии r_i (м) до охраняемого объекта от ряда длиной l_i, взрываемого на i-ую серию

a - технологический шаг между зарядными скважинами, м;

соответствующая

длина ряда,

;

расчетная сейсмобезопасная масса заряда в i-ой серии без учета рассредоточения зарядов,

Q - масса заряда в скважине (кг), принимаемая по технологическим условиям в границах

в том числе при необходимости уточнения до Q_ут, в соотношении

kp - группа крепости взрываемой среды по CH и П;
kc - коэффициент, зависящий от типа и характера застройки охраняемого объекта;
A - среднегеометрическая из величин ширины и длины основания объекта, при r_i/A≥1 принимается A = r_i, м.The specified technical result is achieved by the fact that in the method of blasting near protected objects, including marking the location of the rows of wells within the area of blasted rocks, drilling wells, loading BB, installing the blast network and blasting charges in the wells shortly, marking the area of the blast site and drilling along a biaxial regular grid of wells with the lengths of the segments of the axial lines of the grid between their intersections with the contour of the drilling area equal to

where S is the drilled area of the developed area, m ² , the charges in the wells are grouped in rows and the explosive network is mounted so that in each i-th series of short-blown blasting the number of charges was

Where

estimated number of charges, seismic-safe (without taking into account the effect of their dispersal over the area) at a distance r _i (m) to the protected object from a row of length l _i exploding into the i-th series

a is the technological step between the charging wells, m;

appropriate

row length

;

calculated seismic safety mass of charge in the i-th series without taking into account the dispersion of charges,

Q is the mass of charge in the well (kg), taken according to the technological conditions within

including, if necessary, refinement to Q _ut , in the ratio

kp is the explosive strength group of the CH and P;
kc - coefficient depending on the type and nature of development of the protected facility;
A is the geometric mean of the values of the width and length of the base of the object, with r _i / A≥1 A = r _i , m is taken.

 In the study of the technical level of the invention, no technical solution was found that has the features of the proposed method, on the basis of which it can be considered that the proposed solution meets the criterion of "technical level". The invention is illustrated by drawings, where in FIG. 1 shows a plan for the placement of wells with charges in the developed area for example 1, FIG. 2 is the same for example 2.

 The method is as follows.

где S - обуриваемая площадь разрабатываемого участка, м²,
затем заряженные скважины группируют в ряды, разноудаленные от охраняемых объектов, монтируют взрывную сеть, размещая и взрывая в каждой короткозамедленной серии 5 число зарядов N_i

где

расчетное число зарядов, сейсмобезопасное (без учета эффекта их рассредоточения по площади) на расстоянии r_i (м) до охраняемого объекта от ряда длиной l_i, взрываемого на i-ую серию

соответствующая Nc_i длина ряда,

=a(

-1), м;

- расчетная сейсмобезопасная масса заряда в i-ой серии без учета рассредоточения зарядов,

a - шаг между зарядными скважинами, м;
Q - масса заряда в скважине (кг), принимаемая по технологическим условиям в границах

, необходимые или целесообразные ее уточнения до Q_ут для соблюдения ограничений

сопровождаются уточнением шага до a_ут в соотношении

kp - группа крепости взрываемой среды по CH и П;
kc - коэффициент, зависящий от типа и характера застройки охраняемого объекта.In section 1 intended for explosive development (Fig. 1), charge wells 3 are drilled near the protected object 2 with a diameter, depth, and placement step according to the technological standards adopted to obtain the desired results of the explosion, each well is charged with an explosive mass also of a technologically determined size and a short-blown explosion is made moreover, marking the area of the plot and drilling is carried out on a biaxial regular grid of wells so as to obtain the length of the segments l of its axial lines 4 between their intersections holes with the boundaries of the plot, approximately equal

where S is the drilling area of the developed area, m ² ,
then the charged wells are grouped in rows that are different from the protected objects, the explosive network is mounted, placing and exploding in each short-delayed series 5 the number of charges N _i

Where

estimated number of charges, seismic-safe (without taking into account the effect of their dispersal over the area) at a distance r _i (m) to the protected object from a row of length l _i exploding into the i-th series

corresponding Nc _i row length,

= a (

-1m;

- estimated seismic safety charge mass in the i-th series without taking into account the dispersion of charges,

a is the step between the charging wells, m;
Q is the mass of charge in the well (kg), taken according to the technological conditions within

, necessary or appropriate refinements to Q _ut to comply with the restrictions

accompanied by a refinement of the step to a _ut in the ratio

kp is the explosive strength group of the CH and P;
kc - coefficient depending on the type and nature of development of the protected facility.

For example, for the cases described in the Unified Safety Rules for Blasting (NGO OBT, M., 1993, p. 181), it is accepted:
- single industrial buildings and structures with reinforced concrete or metal frame - 1,
- single buildings up to 2 - 3 floors high with brick and similar walls - 1.5,
- residential villages - 2.

A - среднегеометрическая из величин ширины и длины основания объекта, при r_i/A>1 принимается A = r_i, м.For other types of objects with a known value of the permissible displacement velocity (Vg, m / s)

A is the geometric mean of the values of the width and length of the base of the object, for r _i / A> 1, A = r _i , m is taken.

 Examples of the proposed method of blasting near protected objects.

 Example 1

Мощность разрабатываемого слоя (высота уступа) - 5 м, площадь участка размещения зарядов (обуривания) S = 252 м².Explosive crushing of the remnant of a fortification monolith is carried out (see Fig. 1). The developed concrete-rubble medium is equal in strength to the VII group of soils of the classification CH and P (kp = 7). At a distance of 22 m from the near edge of the blast site, there is a production building with a reinforced concrete frame (kc = 1), with dimensions on the base of 40x30 m

The thickness of the developed layer (step height) is 5 m, the area of the charge placement (drilling) area is S = 252 m ² .

 In accordance with the Normative Handbook on Drilling and Blasting Operations, a short-blown massive explosion of vertical borehole charges with a diameter of 0.11 m, a length of 4.7 m, an ammonite mass of 6ZHV is planned to be Q = 40 kg, with a stem length of 1.7 m and a step between charges of a row - 4.1 m. Moreover, the parameters of the explosion determined by the known method provide a high-quality study of the bottom of the ledge and the output of oversized pieces is not more than 10%.

м каждый. В осях и линиях субпараллельных им с проектным шагом производят бурение скважин на глубину 4,7+1,7= 6,4 м. При этом на данной площади размещается 22 скважины (см. фиг. 1).According to the proposed method, in the project and with surveying marking of the area for drilling, two intersecting axial lines of the well grid with the length of the segments in the area’s dimensions are set

m each. In axes and lines subparallel to them with the design step, wells are drilled to a depth of 4.7 + 1.7 = 6.4 m. At the same time, 22 wells are located on this area (see Fig. 1).

43 - 62/40=1,08 - 1,55,

4,1•((1,08 - 1,55)-1)=0,3 - 2,26

округленно до целого N=1.The wells are charged and the short-circuit blast circuit (SCL) is installed. They are placed in the five groups (series) of short-range explosives (distances of 22-26 m), each charged to the building closest to the building:

43 - 62/40 = 1.08 - 1.55,

4.1 • ((1.08 - 1.55) -1) = 0.3 - 2.26

rounded to the nearest integer N = 1.

4,1•(0,75 - 0,9) = 3,1 - 3,7 м

(с округлением до целого).In the following three series at a distance from the building of 30.4 and 32 m - 2 charges:

4.1 • (0.75 - 0.9) = 3.1 - 3.7 m

(rounded to the nearest integer).

2,3 - 3,

5,3 - 8,2 м,

Наконец, остальные пять зарядов группируют в ряд, взрываемый на одну серию, так как при расстоянии от ближнего заряда группы до OO - 41,5 м число зарядов N_i = 5.Then, in two series at a distance from the protected object (OO) of 35.6 m and 38.8 m (condition A = r is accepted), 3 charges are placed

2,3 - 3,

5.3 - 8.2 m

Finally, the remaining five charges are grouped in a row exploded into one series, since at a distance from the near charge of the group to OO - 41.5 m, the number of charges N _i = 5.

 The sequence of detonation of charges grouped and distributed over a series of short-circuit bombs in an executed manner can be arbitrary if additional conditions are not specified. For example, to limit the expansion of pieces of a fragmented block in the direction of OO, it is preferable to explode the remote charges in the first place (zero series KZV) with a sequential increase in the intervals of KZV as the groups of charges arranged by the method approach OO.

 Example 2

По проекту из технологических нормативов принято: вертикальные скважинные заряды диаметром 0,175 м (безопасность для основания OO обеспечена, так как радиус трещинообразования в данном случае не превышает 10 м при расстоянии ближнего края участка до OO - 12 м), длиной 6,6 м, массой заряда аммонита 6ЖВ в скважине - Q = 140 кг. Шаг между зарядами в ряду - а = 6,2 м.In FIG. 2 shows a diagram of the method when developing a notch in a sandstone massif of group VII according to CH and P (kp = 7) and category III fracturing according to the classification of the MVKVD. An explosion of a block with a ledge height of 8 m and an area of 493 m ^{2 is} designed in the immediate vicinity (r _min = 12 m) from the guarded object - a dam section made of reinforced concrete with a base size of 10 x 20 m. The displacement rate permissible for seismic safety for such an object is 0.5 m / s, which corresponds

According to the project, from technological standards it is accepted: vertical borehole charges with a diameter of 0.175 m (safety for the OO base is ensured, since the radius of crack formation in this case does not exceed 10 m with a distance of the near edge of the section to OO of 12 m), 6.6 m long, weighing 6GV ammonite charge in the well - Q = 140 kg. The step between charges in a row is a = 6.2 m.

м. Бурят скважины по линиям сетки, субпараллельным этим осям, тем самым равномерно размещая (с проектным шагом) в разрабатываемом блоке (см. фиг. 2) 23 скважины (против 26 скважин по субпараллельным контуру линиям).To place wells along the area of the plot, grid axes are set that have the lengths of the segments between intersections with the contour of the drilling site along

m. Drill wells along grid lines subparallel to these axes, thereby evenly placing (with a design step) 23 wells in the block under development (see Fig. 2) (against 26 wells along subparallel circuit lines).

The downhole charges of the design mass are grouped in a series of short-circuit explosions as follows:
- two series of one charge at distances from OO 12 m each;
- two charges per series at a distance of 15 m;
- a group of 6 charges, in which the charge closest to the OO is 17.5 m away (determining the number of charges is carried out analogously to example 1).

N_C=888/140=6,3,
а даже при неограниченной длине ряда l_i достаточно (см. правое ограничение N_C)

Из технологической целесообразности оставляют заряды проектной массы и распределяют их, например, на две серии КЗВ по 6 и 7 шт. в каждой группе (фиг. 2).In the next group of charges with a minimum distance from OO - 23 m, you can include all other charges or increase the mass of charge in the well, because:

N _C = 888/140 = 6.3,
and even with unlimited row length l _{i is} enough (see the right constraint N _C )

From technological feasibility, they leave the projected mass charges and distribute them, for example, into two series of KZVs of 6 and 7 pcs. in each group (Fig. 2).

 The implementation of the proposed method provides the project-specified crushing of the medium, the study of the soles of the ledge, compact camber of the rock mass, pieces directed from the OO, etc. with guaranteed seismic safety of the explosion and saving drilling up to 15% relative to the known method of drilling and blasting.

Claims (1)

A method of blasting explosives near protected objects, including marking the location of the rows of wells within the blast site, drilling wells, loading them with explosives, installing an explosive network and blasting charges in the wells shortly, characterized in that the marking of the area of the blast site and drilling biaxial regular grid of wells with the lengths of the segments of the axial lines of the grid between their intersections with the contour of the drilling area equal to

where S is the drilling area of the developed area, m ² ,
charges in wells are grouped in rows and an explosive network is mounted so that in each i-th series of short-blown blasting, the number of charges is equal to:

Where

the estimated number of charges, seismic safe (without taking into account the effect of their dispersal over the area) at a distance r _i (m) from a series of length l _i exploding into the i-th series, and

determined from the following mathematical expression

where a is the technological step between the charging wells, m;

appropriate

row length;

Q is the mass of charge in the well, kg;

- calculated seismic safety mass of the charge without taking into account the dispersion effect, which is determined by the formula

kg
where kp is the explosive strength group of the classification of SN and P;
kc - coefficient depending on the type and nature of development of the protected facility;
A is the geometric mean of the width and length of the base of the object, for r _i / A> 1, A = r _i , m is taken.

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