MACHINE FOR CONSTRUCTING SHAFTS

Abstract: Method and machine for constructing a vertical shaft in soft rock by means of an excavator (4), comprising the steps of setting the working face of the shaft under water with a constant level so that the lower end of the excavator (4) is kept in the water, spraying concrete towards the shaft well exposed above the water level to form a lining thereon, mixing water and muck excavated from the working face to obtain a slurry and conveying the slurry out of the shaft.

Description: FIELD OF THE INVENTION The present invention relates to a machine for elongating a shaft in soft rock to a great deep shaft of e.g., more than hundred meters, including the features of the first, precharacterizing part of claim 1. PRIOR ART In order to construct such deep shafts, it must be performed steps: a step of approximately vertically excavating a soft rock to form a shaft and then a step of excavating muck generated by excavation of the shaft. With such method, it is critical how to convey efficiently the muck of the shaft from inside to outside because the efficient conveyance of the muck serves to reduce a term and a cost of the construction of the shaft. Methods for conveying the muck have known as follows. (1) A process comprises steps: introducing the muck into a kibble or a bucket in a bottom of the shaft and then lifting them upward to inlet of the shaft. (2) A process comprises steps: filling the shaft with a water and then floating the muck in the water upwards by means of an air-lifting pump. (3) A process comprises steps: filling the shaft with a water, pumping the water including the muck up by a method, called the reverse circulation method, and then separating the muck from the water. Such conventional methods however have drawbacks. With the process (1), the conveyance of the muck can be merely intermittently performed and it takes much time to lift the kibble or the bucket up and down. Therefore, the process (1) cannot be used as a process for constructing efficiently the shaft of a great depth. With the processes (2) and (3), the conveyance of the muck can be continuously performed because the muck can be lifted up to the inlet of the shaft by filling the shaft with the water. However, a peripheral wall of the shaft cannot be subjected to a primary lining or shotcrete made of a concrete because the shaft is filled with the water. Also, an expensive excavator having properties such as watertight, waterproof and the like must be used for construction of the shaft. Further, the excavator must be drawn up when the excavator is maintained outside of the shaft, or the water filled in the shaft must be pumped up when it is maintained in the shaft. With such conventional methods, the muck in the bottom of the shaft cannot be efficiently conveyed outside thereof. DE-A-2942635 discloses a machine for introducing particles into a fluid to be conveyed. This machine includes means for excavating a rock to form a shaft. An excacator is to be positioned at a working face of said shaft. Into the working face of the shaft water will be poured, so that the lower end of said excavator is kept in water and control means are intended to keep water level constant. Water and muck excavated from the working face are to be mixed to obtain a slurry, which will be conveyed to outside of the shaft. To solve the problem of covering the peripheral wall of a shaft by shotcrete FR-A-2374504 suggests to spray concrete toward a peripheral wall of the shaft. The shaft will be constructed by a machine including a flying scaffold with several working plates and connecting members, the scaffold will be positioned in the shaft by sheaves fixed to the uppermost of the plate and the scaffold will be fixed in its working position by grippers fixed to the plates and intended to cooperate with the wall of the shaft. After the shaft has been constructed by the excavator at the lower end of the scaffold the wall of the shaft will be made safe by a liner of concrete made by a spray apparatus at the upper end of the scaffold. So grippers cooperate with the wall of the shaft before protected by a shotcrete. As a consequence of this the material, in which the shaft is to be constructed has to be of minimum hardness i.e. this machine will be fixed safely in it's working position in a shaft which is to be constructed in hard rock. The shaft is to be protected by shotcrete for the time after it's construction. SUMMARY OF THE INVENTION Accordingly it is an object of the invention to provide a machine including the features of the first part of claim 1 which is especially intended to construct a shaft in soft rock. Another object of the present invention is to obviate defects of the conventional machines and provide a machine for constructing efficiently a shaft of a great depth, which can reduce a term and cost of the construction of the shaft. Another object of the present invention is to provide a machine suitable to excavate effectively muck generated by excavating a soft rock from a working face to an upper inlet of the great deep shaft. A machine according to the invention is characterized by the features of the second part of claim 1 and, to have the best solution of the problems by the features of the sub claims. With a machine according to the invention the grippers cooperate with the wall of the shaft after this wall has been protected and hardened by concrete and the machine can be fixed exactly in the shaft which has to be elongated also in case the shaft has to be constructed in soft material making one part of the shaft and making this part deeper can occur in working very efficiently. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described with reference to the accompanying drawings wherein. FIG. 1 is a side view showing a machine for constructing a shaft of the present invention; FIG. 2 is a sectional view taken along the plane II-II of FIG. 1; FIG. 3 is a sectional view taken along the plane III-III of FIG. 1; FIG. 4(a) is a schematic view showing a slurry-conveying apparatus including a first tank and a second tank, in the first tank, a slurry being introduced thereinto and then muck of the slurry being stored therein, and, in the second tank, the muck stored in the second tank being washed away therefrom by the water supplied from the first tank thereto; FIG. 4(b) is a view similar to FIG. 4(a) but showing the slurry-conveying apparatus including the first and second tanks in the contrary state of FIG. 4(a); FIG. 5 is a schematic view showing another embodiment of a slurry-conveying apparatus having three tanks, when the slurry being introduced into a first tank, muck of the slurry being stored in a second tank and conversion introduction of the slurry to storage of the muck or the reverse order; FIG. 6(a) is a side elevational view, in cross section of a three-port-connection-valve for selecting two ways: one way of supplying water for the tank and the other way of drawing off the water from the tank; FIG. 6(b) is a view similar to FIG. 6(a) but showing a fragmentary cross-sectional view of the three-port-connection-valve; FIG. 7 is a graph of showing an open and close condition of the valves corresponding to working time; FIG. 8(a) to 8(e) are a fragmentary cross-sectional view of the valves in open- or close-condition, respectively; and FIG. 9 is a schematic view showing another apparatus having three tanks for conveying slurry to outside of the shaft. DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 to 3 show a machine represented by character A according to this invention, the machine A constructing a great deep shaft having a substantially circular cross-section. In these drawings, numeral 1 denotes a flying scaffold comprising an upper plate 1a, a middle plate 1b, a lower plate 1c and connecting members 1d for connecting between two of the plates 1a to 1c. Each of plates 1a to 1c having a circular cross-section includes a pair of circular faces having the same area as to each other and a peripheral face being formed along a peripheral portion of the circular faces. Each of outer diameter of the plates 1a to 1c is set up to be smaller than an inner diameter of a shaft to be drill. A plural grippers 3 for keeping an attitude of the scaffold 1 are disposed on each peripheral face of the plate at equal intervals. Namely, one ends of the grippers 3 are fixedly connected at the peripheral face of the plate and the other ends are extended to a wall of the shaft to bring the other end into contact with the wall. The upper plate 1a and the middle plate 1b are connected with the connecting members 1d, and the middle plate 1b and the lower plate 1c are connected with the same members as above. For example, as for the upper and middle plates 1a and 1b, opposite ends of the connecting members 1d are fixedly connected at the peripheral portions of the circular faces thereof at equal intervals without rolling the scaffold 1 or twisting it. Three or more of the connecting members 1d are preferably used in connection between two plates. Also, a plural sheaves 2 for suspending the scaffold 1 into the shaft are disposed on the upper plate 1a. As shown in FIG. 1, the flying scaffold 1 is suspended from an upper inlet to a bottom of the shaft by the sheaves 2 and is kept an attitude thereof by the grippers 3. Numeral 4 denotes an excavator having a substantially rod-shaped, comprising opposite ends. One end or an upper end of the excavator 4 is rotatably and downward supported at the central portion of the lower plate 1c. The other end or a lower end extended downward has a bit 4a for excavating soft rock of the bottom of the shaft. A shaft having an optional cross-section can be formed by using the excavator 4 because the bit 4a disposed on the lower end of the excavator 4 can be rotated. A first conveying apparatus 5 or mucking apparatus for conveying muck to be excavated to the following apparatus is disposed on the lower plate 1c, and a second conveying apparatus 6 or slurry-conveying apparatus for conveying slurry suspending the muck to the upper inlet of the shaft is disposed on an upper face of the middle plate 1b. As shown in FIGS. 1 and 3, the first conveying apparatus 5 comprises a pump 7 for generating a jet water, a crasher 10 for crashing the muck drawn up from the bottom of the shaft using the jet water so as to be a small size, a tank 8 for introducing a mixture including the crashed muck and the water, a pump 9 for agitating the mixture to obtain slurry and a slurry pump 11 for conveying the slurry to the second conveying apparatus 6. The pump 7 supplied water including no muck by a pipe 12 is connected with one end of a pipe 13 for ejecting the jet water generated by the pump 7. The other end of the pipe 13 passes through the lower plate 1c to extend downward to a near lower end of a pipe 14 for excavating the muck. One end of the pipe 14 is rotatably supported at the central portion of the lower face of the lower plate 1c and the other end thereof or a lower end is extended downward to be connected with a near position of the bit 4a of the excavator 4 so as to accompany the excavator 4 with the pipe 14. An inlet 15 for drawing up the muck and the water to introduce them into the pipe 14 is disposed at the lowest end of the pipe 14. The muck and the water are drawn up by virtue of an upward flow generated by the jet water of the pump 7 to to be introduced into the pipe 14 and supplied to the crasher 10. In the crasher 10, the muck is ground to have a small grain size. Such muck and the water are introduced into the tank 8 and agitated by the pump 9 to obtain slurry. The slurry is conveyed through a conveyance pipe 16 to the second conveying apparatus 6 by the slurry pump 11. The pipe 12 linked with the pump 7 is connected with a supplement pipe 17. The supplement pipe 17 is connected through a suction pipe 35 of a main pump 22 as described below with a comeback pipe 37. The supplement pipe 17 is also connected with both the tank 8 and the slurry pump 11 in order to supply water thereinto. Further, the supplement pipe 11 is connected with a pipe 18 for supplying water to working face of the shaft. The pipe 18 has a valve 19 for controlling flow rate thereof. Gate opening of the valve 19 is controlled on the basis of water level of the working face measured by a water gauge 20 to adjust content of water supplied to the working face. The water level is determined by a water supplement means 21 for supplying water to the working face so as to be constantly kept. The water supplement means 21 comprises the pipe 18, the valve 19 and the water gauge 20. In FIG. 1, a plural arrows show flows of water or slurry. On the other hand, as shown in FIGS. 1 and 2, the second conveying apparatus 6 comprises the main pump 22, a pair of tanks 23a and 23b, and two filters 24a and 24b disposed in the tanks 23a and 23b, respectively, each filter filtrating slurry filled in the tank to drain water from the tanks. Constitution and actuation of the second conveying apparatus 6 will now be described below in greater detail. The tanks 23a and 23b are connected through check valves 25a and 25b with blanch pipes 16a and 16b divided from the conveyance pipe 16, respectively. The check valves 25a and 25b serve to prevent slurry of the tanks 23a and 23b from flowing into the conveyance pipe 16. The tanks 23a and 23b are also connected through check valves 27a and 27b with blanch pipes 26a and 26b divided from one end of a conveyance pipe 26. The other end of the conveyance pipe 26 is extended to the upper inlet of the shaft in order to convey muck of a slurry to outside of the shaft. The filters 24a and 24b are connected with header pipes 28a and 28b. These pipes 28a and 28b are connected to each other by pipes 29 and 30. The pipe 29 has valves 31 and 32, and the pipe 30 has valves 33 and 34. The suction pipe 35 of the main pump 22 is connected with the pipe 29 between the valves 31 and 32. A delivery pipe 36 of the main pump 22 is connected with the pipe 30 between the valves 33 and 34. In the second conveying apparatus 6, the slurry is conveyed through the filters 24a or 24b in the tanks 23a or 23b to be stored therein. At the same time, the muck of the slurry already reserved in the tanks 23b or 23a is conveyed to outside of the shaft. According to the apparatus 6, the muck can be continuously excavated to convey to outside of the shaft. As shown in FIG. 4(a), when the main pump 22 is actuated under the conditions that the valves 31 and 34 are opened, and that the valves 32 and 33 are closed, the slurry is introduced through the check valve 25a into the tank 23a. The slurry conveyed from the tank 23a is filtrated by the filter 24a, so that muck of the slurry is stored in the tank 23a. The water passed through the filter 24a is conveyed through the filter 24b to the tank 23b and conveyed together the muck already reserved in the tank 23b through the check valve 27a to the conveyance pipe 26 extended to outside of the shaft. After conveying the muck to outside, the valves 31 and 34 are closed, and the valves 32 and 33 are opened. As the result, direction of the slurry flow is contrary to that of the previous flow. In this case, water of the slurry is gradually reduced in the tank 23b and then obtain the muck. On the other hand, the muck already reserved in the tank 23a is conveyed to the conveyance pipe 26. The muck is excavated to outside of the shaft and then is separated the muck from the water. The water separated from the slurry is supplied through the comeback pipe 37 to the main pump 22. A part of the water is also supplied through supplement pipe 17 to the pump 7, the tank 8 and the slurry pump 11 of the first conveying apparatus 5 and the water of the apparatus 5 is further supplied through the supplement pipe 18 to the working face in the shaft by virtue of the water supplement means 21. Furthermore, the thus-described machine A has a spray apparatus 38 for spraying concrete toward the peripheral wall of the shaft to form a shotcrete thereon. As shown in FIG. 1, the apparatus 38 comprises a spraying pipe 39 and a concrete supplement apparatus 40 for supplying the concrete to the spraying pipe 39. Namely, one end of the spraying pipe 39 is rotatably supported at the lower plate 1c of the scaffold 1 so as to rotate along the peripheral wall about an axis of the lower plate 1c and the other end or a lower end of the pipe 39 is capably extended along the axis of the lower plate 1c to the near water face of the shaft. A spraying nozzle 39a is disposed at the lowest end of the pipe 39 and faced to the peripheral wall. The concrete supplement apparatus 40 is disposed on the upper plate 1a. Numeral 41 in FIG. 2 denotes an oil pressure unit for actuating a plural pumps as described above. Also, numeral 42 in FIGS. 2 and 3 denotes a gate for passing machines or goods such as tools and the like through. A dust collector (not shown) is disposed on the upper plate 1a of the scaffold 1. A method for constructing the great deep shaft using the machine A as above-mentioned will now be described below. The flying scaffold 1 is suspended into the shaft by virtue of the sheave 2 and then kept the attitude of the scaffold 1 by using the grippers 3. Water represented by character W is introduced into the bottom of the shaft by the water supplement means 21 so that the machine A is partially immersed in the water W, namely only the bit 4a of the excavator 4 is submerged therein. Subsequently, the drilling is performed by the excavator 4 and then the first and second conveying apparatuses 5 and 6 are actuated, in the order. As described above, the muck drilled from the working face of the shaft are changed into the slurry to be excavated to outside of the shaft. In the excavation of the slurry, although the water W is reduced because the water W is sucked up together the muck, the water level of the water W is constantly kept by virtue of the water supplement means 21. At the same time, the peripheral wall exposed above the face of the water W is subjected to spray of concrete to form the primary shotcrete thereon. In this case, distance of the water face to the wall being performed the primary shotcrete is preferably shorten. For example, the distance represented by character 1 is between about 1 meter and 3 meters. According to the method as described above, the machine A including the excavator 4 and another apparatus assembled thereinto is required of having no properties such as watertight, waterproof and the like because the level of the water W is constantly kept so that the machine A is partially immersed in the water W. Also, since the water W is shallow, the maintenance of the machine A such as exchange of bits and the like can be easily and promptly performed in the bottom of the shaft or a shaft to be constructed. Further, the muck of the working of the face can be continuously and efficiently excavated by means of the first and second conveying apparatuses 5 and 6 in comparison with conventional method using kibbles or buckets to excavate the muck. Especially, the second conveying apparatus 6 can have an output power sufficient for lifting up a large amount of the muck from the bottom of the shaft to the upper inlet thereof, so it can be reduced a term and a cost of the construction of the shaft. The main pump 21 for conveying slurry upward is subjected to water pressure corresponding to distance between the pump 21 and the upper inlet of the shaft or depth of the pump 21. Therefore, the output power of the pump 21 can be reduced by the water pressure subjected thereto to save energy generated thereby. According to the method, a shotcrete can be promptly formed on the peripheral wall of the shaft by spraying concrete toward the peripheral wall above the water level of the water W before the peripheral wall is broken. Therefore, the excavation according to the method can be performed in safety even if water is suddenly sprang up from the working face. As for the constitutions of the scaffold 1, the excavator 4, the first and second conveying apparatuses 5 and 6, the water supplement means 21 and the spray apparatus 38 as described above, they should in no way be construed as limiting the present invention. Meanwhile, one or more of the second conveying apparatus 6 as relaying apparatuses may be replaced on the way to the upper inlet of the shaft on the occasion that a shaft to be drilled has a great deep, and that the slurry cannot be conveyed by using the apparatus 6 having power insufficient for conveying it from a bottom of the shaft to an upper inlet thereof. FIGS. 5 to 8 show another variation of the second conveying apparatus 6 as described above. Numeral 100 denotes a primary conveying apparatus. The primary conveying apparatus 100 comprises a first jet pump 120, an actuation pump 121, a water supplement pipe 122, a conveyance pipe 123 and an agitation tank 124. The jet pump 120 is a pump for pumping up muck together the water W by suction generated because of a jet water supplied through the water supplement pipe 122 from the actuation pump 121 and then conveying the muck through the conveyance pipe 123 to the agitation tank 124. By virtue of the agitation tank 124, the muck is mixed with water to be obtained slurry. The slurry is introduced through a slurry supplement pipe 125 into three kinds of tanks Ta, Tb and Tc, and top water of the slurry in the tank 124 is repeatedly come back through a comeback pipe 126 to the working face. Each of the pressure tanks Ta, Tb and Tc has contents sufficient for introducing a predetermined amount of the slurry. Although each tank is shown as a horizontal type in FIG. 5, it is constructed in a vertical one in practical use. Bottoms of the pressure tanks Ta, Tb and Tc are connected through check valves 127a, 127b and 127c with the slurry supplement pipe 125, respectively. Tops of the pressure tanks Ta, Tb and Tc are connected with one ends of header pipes 130a, 130b and 130c, respectively. The other ends of the header pipe 130a, 130b and 130c are connected with main ports P₁ of three-port-connection-valves Va, Vb and Vc. Further, filters Fa, Fb and Fc for passing through water of the slurry and for barring muck thereof are disposed on the way between the pressure tanks and the three-port-connection-valves, respectively. As shown in FIG. 6, each of the three-port-connection-valves Va, Vb and Vc comprises a substantially cylindrical valve cage 140 and a substantially spherical valve element 141 rotatably disposed therein. The valve cage 140 includes the main port P₁ being disposed vertically at the bottom thereof, an outlet port P₂ and an inlet port P₃ each being disposed horizontally at the side portions. A lever 142 for rotating the valve element 141 is connected with a top portion of the valve element 141. By operating the lever 142, the outlet port P₂ or the inlet port P₃ and the main port P₁ can be selectively connected to each other. FIG. 6 shows the three-port-connection-valve connecting the main port P₁ with the inlet port P₃. As shown in FIG. 5, the outlet ports P₂ of the three-port-connection-valves Va, Vb and Vc are connected with blanch pipes 150a, 150b and 150c divided from a water supplement pipe 150, respectively. The inlet ports P₃ are connected with blanch pipes 151a, 151b and 151c divided from a drain pipe 151, respectively. A second actuation pump 152 is disposed on the way of the water supplement pipe 150, and a second jet pump 153 having property and power the same as the first jet pump 120 as described above is disposed on the way of the drain pipe 151. The actuation pump 152 is a pump for supplying water through the three port connection vale and the filter to one of the pressure tanks, e.g., the tank Ta as shown in FIG. 5, to thereby wash away the muck stored in the tank Ta. The second jet pump 153 is a pump for pumping up only water through the filter and the three-port-connection-valve from one of the tanks, e.g., the tank Tc as shown in FIG. 5, by using suction generated because of a jet water supplied through a jet water supplement pipe 154 from the first actuation pump 121, to thereby store muck of the slurry in the tank Tc. The jet pump 153 is a pump for coming back the water pumped up through a comeback pipe 155 to the first actuation pump 121, and further for supplying a part of the water pumped up, through a water supplement pipe 156 to the working face. An amount of the water supplied from the jet pump 153 to the working face is controlled on the basis of a gate opening of a valve 157 disposed on the way of the water supplement pipe 156 so that the water level of the working face is constantly kept. An inlet of the main pump 152 and an outlet of the jet pump 153 are connected by a pipe 158 for supplying directly water of the water supplement pipe 150 to the working face. One of the three-port-connection-valves Va, Vb and Vc is set up to synchronize with another. The synchronization of the valves Va, Vb and Vc will now be described below with reference to FIGS. 7 and 8. The gate opening of the valves Va, Vb and Vc, which correspond to the working time, are shown in the order from upper to lower portion of FIG. 7. Opening and closing of the valve are repeatedly performed at a cycle time or period represented by character T. The valves are actuated to have a time lag represented by character t₁ to each other. For example, the valve Va is actuated as follows. The outlet port P₂ is full opened as shown in FIG. 8(a) during the time t₁. Subsequently, the outlet port P₂ is gradually closed and then the inlet port P₃ is gradually opened during a time t₂. As the result, the inlet port P₃ is full opened as shown in FIG. 8(b) and then this state is kept during a time t₃. Subsequently, the inlet port P₃ is gradually closed as shown in FIG. 8(c) and the inlet and outlet ports P₃ and P₂ are full closed together as shown in FIG. 8(d) and the outlet port P₂ is gradually opened as shown in FIG. 8(e) and then the outlet port P₂ is full closed again as shown in FIG. 8(a). The same procedures as the valve Va are repeated by the valve Vb with a delayed time t₁ and the same procedures as the valve Vb are repeated by the valve Vc with the delayed time t₁. Namely, the outlet port P₂ of the valve Vb is full opened as a state of full opening that of the valve Va is finished. The outlet port P₂ of the valve Vc is full opened as the state of full opening that of the valve Vb is finished. Further, the outlet port P₂ of the valve Va is full opened again as the state of full opening that of the valve Vc is finished. Also, the same procedures as the outlet ports P₂ are repeated by the inlet ports P₃. When only one of the outlet ports P₂ of the three valves is full opened, one of the inlet ports P₃ of another two valves is full opened and the remainder is in gradual conversion full-opening from the inlet port P₃ to the outlet port P₂. As for the primary conveying apparatus 100 provided the valves Va, Vb and Vc as described above, flows of water conveyed by the main pump 152 and those of water pumped up into the slurry are changed just in time. Therefore, the slurry obtained in the agitation tank 124 is pumped up by one of the pressure tank Ta, Tb and Tc to be filled thereinto. At the same time, the muck filled into another two tanks is washed away. At the same time, the slurry introduced into the remainder is in gradual conversion from pumping-up to washing-away. As shown in FIG. 6, when the outlet port P₂ of the valve Va is full opened, the inlet port P₃ of the valve Vc is full opened. At this time, the water conveyed from the main pump 152 is introduced through the filter Fa into the tank Ta. Also, the muck reserved into the tank Ta is washed away through a pipe 129 toward the secondary conveying apparatus 200. At the same time, the water of the slurry reserved into the tank Tc is pumped up through the filter Fc by the jet pump 153, and the slurry of the agitation tank 124 is sucked up into the tank Tc to be increased gradually the content of the muck in the tank Tc. At this time, the valve Vb is in gradual conversion from pumping-up to washing-away. Therefore, as the muck is finished washing away from the tank Ta by closing the outlet port P₂ of the valve Va, the muck is begun washing away from the tank Tb. At the same time, the tank Ta is begun pumping up the muck thereinto and the tank Tc is begun to be in gradual conversion of pumping-up to washing-away. According to the primary conveying apparatus 100, three kinds of the tanks Ta, Tb and Tc can perform the following works at the same time, respectively. Namely, one of the tanks Ta, Tb and Tc washes away the muck, one of another two tanks pumps up the slurry, and the remainder is in gradual conversion of pumping-up to washing-away. By virtue of thus works of the tanks Ta, Tb and Tc, the muck can be continuously washed away from one of the tanks. Therefore, the primary conveying apparatus 100 can efficiently convey the muck of the working face to a secondary conveying apparatus 200. The secondary conveying apparatus 200 is an apparatus for further conveying the slurry obtained by the primary conveying apparatus 100 to the upper inlet of the shaft, comprising the essentially same elements as the primary conveying apparatus 100 except that the actuation pump 121 and the agitation tank 124 are omitted from the apparatus 100 and that a storage tank 160 is added thereinto. Namely, the apparatus 200 comprises three kinds of pressure tanks Ta′, Tb′ and Tc′ and a main pump 61. The tanks Ta′, Tb′ and Tc′ have filters Fa′, Fb′ and Fc′, and three-port-connection-valves Va′, Vb′ and Vc′, respectively. According to the apparatus 200, the slurry conveyed from the apparatus 100 is introduced through the pipe 129 into one of the tanks Ta′, Tb′ and Tc′ to reserve therein and the slurry reserved in one of another two tanks is washed away by the water supplied from the main pump 161 to be conveyed to the upper inlet of the shaft. At the same time, the remainder of the tanks is begun to be in gradual conversion from introduction of the slurry to washing-away. The slurry conveyed to the upper inlet of the shaft by the secondary conveying apparatus 200 is introduced into a disposal tank 162 and then subjected to separation and the resulting solid or muck is suitably disposed. The water separated from the slurry is come back again to the main pump 161 and a part of the water is directly supplied through a water supplement pipe 163 to the storage tank 160. Also, the water of the slurry filtrated by the filters Fa′, Fb′ and Fc′ is stored in the storage tank 160 and then come back through the water supplement pipe 150 to the main pump 152 of the primary conveying apparatus 100. According to the method of the present invention using the primary conveying apparatus 100, the slurry drilled from the working face can be continuously excavated to outside of the shaft. Also, a great deep shaft having a depth of, e.g., more than hundreds meters can be efficiently constructed by disposing relay apparatuses such as the secondary conveying apparatus 200 and the like on the way of the shaft on the basis of the depth of the shaft. As for the main pumps 152 and 161, the main pump 152 is subjected to hydrostatic pressure corresponding to height therefrom to the storage tank 160, and the main pump 161 is subjected to hydrostatic pressure corresponding to height therefrom to the disposal tank 162. Therefore, they can sufficiently work if they have power of overcoming friction caused between the slurry and an inner wall of the pipes and corresponding difference of density between the water and the slurry. They must have no power for conveying muck from a bottom of the shaft to the inlet. Also, they have no risk of breaking down because only water filtrated by the filters passes therethrough. FIG. 9 shows another variation of the primary and secondary conveying apparatuses as described above. A system comprising a primary and secondary conveying apparatuses 100′ and 200′ serves to drain a large amount of flood, in addition to conveying muck to outside of the shaft. The primary conveying apparatus 100′ has a drain pipe 170 for connecting the actuation pump 121 with the water supplement pipe 158, and the secondary conveying apparatus 200′ has a bypass pipe 171 for connecting an inlet of the storage tank 160 with the water supplement pipe 163. A drain pump is disposed on the way of the bypass pipe 171. Numerals 173 to 184 denote valves disposed on the way of the pipes, respectively. The ordinary works of the system as shown in FIG. 9 are substantially identical to those of the system as shown in FIG. 5. However, when the flood is suddenly generated, the following works are performed. Namely, the valves 173, 175, 176, 179, 180 and 182 are opened, and the valves 157, 174, 177, 178, 181, 183 and 184 are closed, respectively. At the same time, the three-port-connection-valves Va, Vb, Vc, Va′, Vb′ and Vc′ are worked in ordinary ways and the jet pumps 120 and 153, the actuation pump 121, the main pump 152 and 161 and the drain pump 172 are worked, respectively. As the result, the water W can be pumped up from the working face by the jet pump 120 and further pumped up through one tank, e.g., the tank Tc as shown in FIG. 9, the jet pump 153, the actuation pump 121, the main pump 152, another tank, e.g., the tank Ta as shown in FIG. 9 to the secondary conveying apparatus 200′. In the apparatus 200′, the pumped-up water W is pumped up through one tank, e.g., the tank Tc′ as shown in FIG. 9, the drain pump 172, the main pump 161 and another tank, e.g., the tank Ta′ as shown in FIG. 9 to the disposal tank 162. According to this variation, the system can be used as the drainage system in case of emergencies such as floods and the like. In the system as described above, although the jet pump 153 is used for pumping up the slurry to introduce it into the pressure tank, a pump, e.g., a slurry pump disposed on the way of the slurry supplement pipe 125 may be used for pumping up it without using the jet pump 153. Further, although the jet pumps 120 and 153 have many advantages such as almost no mechanical trouble, almost maintenance free and the like in comparison with the slurry pump, the slurry pump may be used.

Claims: An excavating machine for elongating a shaft in soft rock, including an excavator (4) with a bit (4a), a flying scaffold (1) supporting the excavator and a mucking apparatus for mixing water and muck excavated from the working face to obtain a slurry and for pumping said slurry upward; a slurry-conveying apparatus for conveying said slurry to outside of the shaft on several plates (1a, 1b, 1c) of the scaffold (1) connected by connecting means (1d), further including sheaves (2) fixed to the uppermost plate (1a) for positioning the flying scaffold (1) in the shaft in relation to the ground face of the shaft and including grippers (3) fixed to the plates (1a, 1b, 1c) for cooperation with the peripheral wall of the shaft in the working position of the bit (4a) of the excavator and including a spraying apparatus (38) for spraying concrete towards the peripheral wall of the shaft to form a shotcrete on the wall, characterized by water gauge means (20) and water supplement means (21) including valve means (19) controlled by the water gauge means (20) for supplying water to the ground face of the shaft with the water level being constantly shortly above the working area of the bit (4a); the spraying nozzle (39a) of the spraying apparatus (38) being supported at the lower side of the lowermost of the plates of the scaffold (1) at the one end of the spraying pipe (39), said spraying nozzle (39a) is disposed above the bit (4a) and below the grippers (3) of the lowermost plate (1c), the other end of which is supported at the lower side of the same plate (1c) rotatably around an axis of the lowermost plate (1c) to form shotcrete on a part of the wall of the shaft positioned between water level and the grippers (3) of the lowermost plate (1c). A machine according to claim 1, wherein water supplement means (21) comprise a pump (7) for supplying water to said ground face of the shaft, a supplement pipe having opposite ends, one end being linked with said pump and the other end (18) being extended to said ground face, wherein the amount of water added to the shaft is controlled by the valve means (19) disposed on the way of said supplement pipe, and wherein the water level in the shaft is measured by a water gauge (20). A machine according to claim 1 or 2, wherein a mixing apparatus comprise a mixing pump for pumping up fragmented soft rock and water of said ground face, a crusher (10) for crushing said fragmented soft rock pumped up by said mixing pump, and an agitating pump (9) for agitating the mixture of said crushed fragmented soft rock and water to produce the slurry. A machine according to one of claims 1 to 3, including filtering means for filtering said slurry to separate fragmented soft rock from water of said slurry, said filtering means include a tank (23b) for storing the water separated from said slurry and means for conveying said fragmented soft rock separated from said slurry to the outside of said shaft. A machine according to one of claims 1 to 4, wherein the slurry-conveying apparatus comprise a pair of tanks and a main pump for pumping slurry from the ground face alternately into the pair of tanks, the slurry introduced into one of the tanks is to be filtered, thereby separating water from the slurry, spraying the separated water into the other tank through the main pump and thereby sending both the supplied water and slurry in the other tank to the outside of the shaft. A machine according to one of claims 1 to 4, wherein the slurry-conveying apparatus comprise three tanks, a first pump, and a second pump for pumping slurry from the ground face into each of the tanks in turn by means of the first pump, filtering the slurry introduced into one of the tanks and sending the filtered slurry to the first pump, supplying water into one of the other two tanks by means of the second pump and thereby washing slurry out of said one of the other two tanks so as to send the slurry to the outside of the shaft, and changing the other tank from its pumping state into its washing-away state, whereby the pumping, washing, and the changing are performed simultaneously. A machine according to claim 1, wherein the controlling of the water comprises measuring the water depth in the shaft, and adding water to the shaft on the basis of the water level measurement.

Inventors: FUJINAGA, TOMOSABURO SHIMIZU CONSTRUCTION CO.,LTD., HIDA, TSUGIO SHIMIZU CONSTRUCTION CO., LTD., KAWATA, TAKASHI SHIMIZU CONSTRUCTION CO., LTD., KIKUCHI, YUICHI SHIMIZU CONSTRUCTION CO., LTD., MIYAZAKI, AKIRA SHIMIZU CONSTRUCTION CO., LTD., MIZUTANI, FUMITOSHI SHIMIZU CONSTRUCTION CO., LTD., OHARA, YOSHIYUKI SHIMIZU CONSTRUCTION CO., LTD., SHIMAZAKI, SHIROYASU SHIMIZU CONSTRUCTION CO.,LTD.
Applicants: SHIMIZU CONSTRUCTION CO. LTD.
Application year: 1988
Main classification: E21D1
IPC codes: E21D1, E21D5, E21F13