The process of the dark artificial frozen soil controlled blasting of thick surface soil construction freezing method
Technical field
The present invention relates to a kind of dark thick surface soil freeze-wellboring technology, exactly is the process of the artificial frozen soil controlled blasting of dark thick surface soil construction freezing method.
Background technology
German engineer F.H.Poetsch got the colliery in German Alba in 1883, and having dug the degree of depth with freezing process is the pit shaft of 103m, has obtained the patent of freeze-wellboring, and this technical communicator arrives many countries in the world afterwards.Nineteen fifty-five, China has dug with freezing process and has opened Linxi, Luan ventilating shaft, the clean diameter 5m of pit shaft, and depth of freezing 105m, after this China scientific and technical personnel have begun the freeze-wellboring Study on Technology.Nearly 50 years, obtained plentiful and substantial achievement in research, the 430 remainder freezing engineerings of always having built together, comprise the maximum frozen depth 415m eighties Huainan Pan three-east ventilating shaft and the nineties maximum frozen depth 435m Henan summer mining area Chen Si building auxiliary shaft forever, at present the thick alluvium that passed through of freeze-wellboring is that ore deposit, Jixi, Shandong auxiliary shaft is 458.5m, depth of freezing 488m, China's freeze-wellboring technology has striden into world's rank of advanced units.External in the colliery depth of freezing the darkest be No. 1 well auxiliary shaft of Lublin of Poland, become well 6.0m, depth of freezing 725m; Freezing the unsettled the 3rd is and the Quaternary system stratum, and representative is No. 8 wells of Sophia Jacba of Germany, depth of freezing 558m; Freeze basement rock and layer of sand, clay alternating layers, representative is No. 2 wells of Corvidae husband iron ore of the former Soviet Union, and depth of freezing 620m, the Bo Er of Britain are than sylvite ore, and the Freezing stratum as rapid degree of depth reaches 930m.Along with applying of construction freezing method technology and continuing to increase of the depth of freezing; frost wall is as the assurance of protection pit shaft safe construction; must have enough intensity and thickness; the high strength of frost wall and small deformation also are to prevent fracture of freezing pipe, safeguard the necessary condition of the stability of frost wall self.Therefore, mostly adopt in deeply feeling native freezing shaft at present and strengthen freezing, the way that improves frost wall intensity solves the safety issue of construction freezing method, and has obtained good project benefit in practice.But the reduction solidification point certainly will cause the frozen soil that enters in the shaft excavation section to increase to increase frost wall intensity, and pit shaft freezes reality substantially sometimes, has so just brought great difficulty to driving.Excavate because the excavation of present domestic frozen soil is manual type basically, freeze real soil layer and increased the weight of working strength of workers greatly, and driving speed reduces significantly, the economic benefit of unit in charge of construction is had a strong impact on.For example certain colliery is shaft development, the clean diameter 4.5m of main shaft, and pit shaft passes thickness of surface soil 289m in the Quaternary Period, and table soil section adopts construction freezing method, and the depth of freezing is 320m.The waste footpath of top driving 6.1m, when shaft excavation during to well depth 110m, the full section of pit shaft freezes reality.Owing to be mainly tephrosious calcium clay layer between well depth 100~150m, this layer soil intensity after freezing is very high, and well group temperature-averaging was-9 ℃ at that time, and the distortion of well group is minimum.The working face hand digging is very difficult, and a per-shift drilling depth is 200mm, and labor strength is very big, and efficient is extremely low.This shows that the pit shaft freeze section freezes reality, reduced the distortion of frost wall, improved the intensity of frozen soil and the stability of frost wall, guaranteed the safety of freezing pipe, be good aspect, but the problem that exists is to have brought difficulty to driving.Hand digging frozen soil labour intensity is big, and efficient is low.Blasting method is the effective measures that improve driving speed, but exists the danger of bad freezing pipe of shake.Look into the domestic and international novelty assessment report of new consulting unit from country-level science and technology and know, the problem of the current artificial frozen soil controlled blasting of system research of also having no talent both at home and abroad.
Summary of the invention
The objective of the invention is: provide a kind of and in the native freeze-wellboring construction of deep unstable table, can guarantee that frost wall is stable, can guarantee the process of the artificial frozen soil controlled blasting of freezing pipe safety again.
The technical solution that realizes the object of the invention is as follows:
The process of the dark artificial frozen soil controlled blasting of thick surface soil construction freezing method comprises the steps:
A, freeze real pit shaft circle centre position at full section the above snubber of one circle is set, snubber is uniform, and spacing is 600-630mm between the snubber, and dark is 1.4-1.8m; One circle periphery hole is set on the waste footpath of excavation, and periphery hole is uniform, and spacing is 450-500mm between the periphery hole, and eye is dark to be 1.2-1.6m; At the reliever that is provided with between periphery hole and the snubber more than the circle, spacing is 650-750mm between the reliever, and eye is dark to be 1.2-1.6m;
B, snubber adopt the upper and lower part to separate the short-delay blasting of powder charge intraocular, and explosive payload is 0.3Kg/m; Periphery hole adopts powder stick batten air column decoupling charge mode, and concrete operations are at powder stick and seal the batten that a diameter is 10-15mm is set between the stemming that explosive payload is 0.15Kg/m; The explosive payload of reliever is 0.25Kg/m;
C, assurance freezing pipe safety, adopting snubber intraocular millisecond elementary errors, other borehole is the full section once detonation of same section detonator for half second delay, same circle borehole between eye.
When the shaft excavation diameter of excavation is 6m when above, freeze real pit shaft circle centre position at full section two circle snubbers, the two above relievers of circle and a circle periphery hole are set.
The snubber eye is dark when being 1.6m, and its charging means is: borehole top explosive payload is 0.2Kg/m, and the bottom explosive payload is 0.28Kg/m, and the intraocular millisecond detonating time is 20ms.
To the deflection freezing pipe, when periphery hole during less than 0.6m, adopts the close drilling method apart from the radial distance of freezing pipe, the distance between the adjacent peripheral eye is 200-300mm, and not powder charge in the periphery hole.
When periphery hole is 0.6-1.0m apart from the radial distance of freezing pipe, eye is dark when be 1.2m, and the distance between the adjacent peripheral eye is 400-450mm, and the interior explosive payload of periphery hole is 0.10Kg/m.
Whether cutting types rationally directly influences demolition effect.The snubber explosive payload is relatively large, in order to reduce once neat quick-fried dose, adopts the influence of upper and lower separately powder charge intraocular short-delay blasting minimizing to freezing pipe.Full borehole is divided into two sections, and the bottom explosive payload is greater than top, behind the explosive initiation of top, form new scope of freedom moment, the bottom explosive that detonates to make full use of the residual stress in the scope of freedom and the frozen soil, changes powder charge energy distribution in the borehole, increase the slotting volume, reduce the throwing height, reduce influence, accurately detonate in order to guarantee snubber to freezing pipe, the big gun head is made two big gun head modes that adopt, and the millisecond detonating time is determined according to the frozen soil characteristic.
It rationally is the key of decision Frozen-soil Blasting quality that eye position, eye distance and the explosive payload of periphery hole are selected, and is again the key that guarantees freezing pipe safety.According to experimental study, optimum concentration coefficient of holes is 0.9, and the quick-fried layer thickness of light is excessive, and the fragmentation preferably of the quick-fried layer of light got off, even produces bulk, and too small, back wave will damage the frozen soil that need keep, and influences quick-fried quality of light and frozen soil stability.Spacing is too small, increases the perforating workload, the excessive moulding that also is unfavorable for pit shaft.The periphery hole charge constitution adopts powder stick batten air column decoupling charge, and air column adopts batten to form between the stemming sealing on stemming and the powder stick.The cushioning effect of air dielectric greatly reduces the compression failure degree of hole wall periphery frozen soil.Because periphery hole is nearest apart from freezing pipe, the explosive payload of control periphery hole.
Above-mentioned part method is to adopt the concrete measure of close drilling method protection deflection freezing pipe.To adopt the main difficult technical of drilling and blasting method be the safety that guarantees freezing pipe freezing to show the soil section.If fracture of freezing pipe can bring great difficulty even make whole engineering failure to shaft construction.When the freezing pipe deflection, frost wall effective thickness attenuate, strength reduction should careful explosion at deflection freezing pipe place.Before blowing out, should correctly calculate the deflection distance and bearing of each deflection freezing pipe, help the position that observably marks the deflection freezing pipe by result of calculation, remind the workman when powder charge, to be noted, adopt the close drilling method at this position upper periphery eye at well.
Useful technique effect of the present invention is embodied in four aspects:
1. adopt process method construction of the present invention, under the safety condition that guarantees freezing pipe, alleviated labor strength, driving speed improves 4-6 doubly.
2. snubber adopts up and down separately powder charge intraocular short-delay blasting can increase the explosion and crushing degree of depth, reduces explosive specific charge, helps the safety of freezing pipe.
3. frozen soil photoface exploision, concentration coefficient of holes are that 0.9 left and right sides photoface exploision effect is better; Adopt powder stick batten air column decoupling charge structure, can improve the photoface exploision effect.
4. determined that artificial Frozen-soil Blasting guarantees the explosive payload of freezing pipe safety.Determine best dose under certain buried depth and the best buried depth under certain dose.
Description of drawings
Fig. 1 is the present invention's full section borehole layout drawing and the freezing pipe location drawing,
Fig. 2 is a snubber charge constitution schematic diagram,
Fig. 3 is a periphery hole charge constitution schematic diagram.
The specific embodiment
Below by the engineering construction example, in conjunction with the accompanying drawings the present invention is elaborated.
Project profile
Certain colliery is shaft development, the clean diameter 4.5m of main shaft, and pit shaft passes thickness of surface soil 289m in the Quaternary Period, and table soil section adopts construction freezing method, and the depth of freezing is 320m.Waste diameter 6.1m is tunneled on top, and when shaft excavation during to well depth 110m, the full section of pit shaft freezes reality.Owing to be mainly tephrosious calcium clay layer between well depth 100~150m, this layer soil intensity after freezing is very high, and well group temperature-averaging was-9 ℃ at that time, and the distortion of well group is few.The working face hand digging is very difficult, and a per-shift drilling depth is 200mm, and labor strength is very big, and efficient is extremely low.In order to alleviate labor strength, accelerate driving speed, the controlled blasting method is adopted in decision.This well tunneled half the degree of depth of not enough freeze section at that time, did not allow freezing pipe fracture, fracture phenomena to occur, otherwise can't save.Before the explosion driving is implemented, carried out comprehensive demonstration and deep analysis discussion, worked out detailed, reliable arrangement and method for construction and safety measure in conjunction with our experimental study.Guaranteeing successfully to have finished the tunneling construction of this well freeze section under the freezing pipe security situation.
Explosion preparation
For guarantee the explosion driving safe, carry out smoothly, guarantee freezing pipe safety, at first want the deflection situation of freezing pipe in the labor bursting work district, calculate the beeline that every freezing pipe is helped apart from well, determine the freezing pipe of dangerous freezing pipe and focused protection.Learn that according to the freezing pipe deflection figure of driving face place freezing pipe all more than 1.9m, has two thermometer holes to be 1.0mm apart from well group is nearer apart from the waste footpath of driving, these two thermometer holes must protect, and everything goes well with your work carries out with the monitoring analysis of guaranteeing the bottom frost wall.Carrying out explosion in such distance is comparison danger.According to achievement in research, take suitable method, guarantee thermometer hole safety.
Because original frozen soil section driving adopts the hand digging mode, uses blasting method instead and must prepare explosive and jewel hole facility, air rock drill and electric coal drill combination drilling are adopted in decision.Explosive is selected rock dynamite for use No. 2, and density is 950~1100Kg/m
3, explosion velocity is 3600~3800m/s.
Blasting method
According to the characteristic of shaft section and frozen clay layer, design blasting parameter and borehole layout drawing.Other is the full face blasting method that half second delay between eye, same circle borehole adopt same section detonator to adopt snubber intraocular elementary errors.
The snubber explosive payload is relatively large, in order to reduce once neat quick-fried dose, adopts up and down separately powder charge intraocular short-delay blasting minimizing to the influence of freezing pipe.Full borehole is divided into two parts up and down, the lower part explosive payload is greater than top, behind the explosive initiation of top, form new scope of freedom moment, the lower part explosive that detonates is to make full use of the residual stress in the scope of freedom and the frozen soil, change powder charge energy distribution in the borehole, increase the slotting volume, reduce the throwing height, reduce influence freezing pipe.The snubber eye is dark to be 1.4m, and the eye spacing is 630mm, and every explosive payload is 0.42Kg, and top is 0.20Kg, and the bottom is 0.22Kg.The reliever degree of depth is 1.2m, and the eye spacing is 700mm, and every explosive payload is 0.3Kg, i.e. two volume medicines.
It rationally is the key that guarantees freezing pipe safety that eye position, eye distance and the explosive payload of periphery hole are selected.In conjunction with field experience, the quick-fried layer thickness of light is usually slightly larger than spacing according to experimental study, and concentration coefficient of holes is 0.9, and spacing is 500mm, and eye is dark to be 1.2m, and explosive payload is 0.18Kg, and periphery hole and reliever spacing are 550mm.
The periphery hole charge constitution adopts powder stick batten air column decoupling charge.Because periphery hole is nearest apart from freezing pipe, should reduce the explosive payload of periphery hole.Manually open group in order to save, the eye position of periphery hole is arranged on the waste footpath, but beats straight eye when perforating as far as possible, draws the position on eyeground, carries out effect Analysis after the explosion, in time adjusts blasting parameter.Referring to Fig. 1, Fig. 2 and Fig. 3.
Adopt full section once detonation, detonator is half second delay detonator, and makes every section explosive quantity about equally.Should pursue a conducting for detonator, and detection resistance value, organize into groups by its resistance size, use in batches, can avoid the blown-out shot phenomenon effectively like this.
Demolition effect is: blast hole utilization factor 95%, every cyclic advance 1150mm.
The measure of protection freezing pipe
To adopt the main difficult technical of drilling and blasting method be the safety that guarantees freezing pipe freezing to show the soil section.If fracture of freezing pipe can bring great difficulty even make the construction failure to shaft construction.Should careful explosion at deflection freezing pipe place.When periphery hole during less than 0.6m, adopts the close drilling method apart from the radial distance of freezing pipe, the distance between the adjacent peripheral eye is 200mm, and not powder charge in the periphery hole.When periphery hole is 0.6-1.0m apart from the radial distance of freezing pipe, eye is dark when be 1.2m, and the distance between the adjacent peripheral eye is 400mm, and the interior explosive payload of periphery hole is 0.10Kg/m.In addition, strengthen unit in charge of construction and freeze the cooperation of unit, notice is freezed unit and is turned off all feed pipe valves before blowing out, and has blown out the back to check that brine tank water level and well group have or not the salt solution leakage phenomenon, when determining can't harm, open the feed pipe valve again.In going out the cash process, conscientiously check well group situation, if any water outlet or yellow water mark occurs and should close the freezing pipe valve immediately, ascertain the reason.
Conclusion
(1) adopt the inventive method, the explosion driving in the frozen clay layer has not only guaranteed the safety of freezing pipe and temperature tube, and has alleviated working strength of workers greatly, has improved driving speed 5-6 doubly.
(2) adopt up and down the separately firing order of powder charge intraocular elementary errors cutting method and rationally full section half second delay, obvious improved demolition effect, because this special media of frozen soil, blast hole utilization factor can reach more than 95%.Adopt rational photoface exploision parameter and powder stick batten air column decoupling charge structure, increased the eye trace rate of periphery hole, reduced the brushing amount.The frozen soil section adopts this special blasting method, has guaranteed the safety of freezing pipe, has improved speed of application.
(3) crux of Frozen-soil Blasting driving is the safety that will guarantee freezing pipe, and the explosion of rationally controlling periphery hole is the key of protection freezing pipe.At first to correctly grasp the deflection situation of freezing pipe, determine that emphasis keeps object, accomplish to shoot the arrow at the target.The position, hole of laying special stress on protecting freezing pipe observably is marked on well helps, remind the workman when powder charge, to be noted at any time.According to the practice of this separate explosion tunneling construction, the eye position of periphery hole is arranged into waste footpath is fine, when the 0.9m, freezing pipe is still safe periphery hole apart from freezing pipe.
(4) organization of labour structure of having broken hand digging is tunneled in the explosion of freezing topsoil, and well-organized construction can guarantee construction safety, can improve drivage efficiency again.