JP3481508B2 - Stone masonry retaining wall reinforcement method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing a masonry retaining wall which is weakened so as to withstand use. 2. Description of the Related Art A stone masonry retaining wall made of a natural stone, a processed stone of a natural material, a stone-like concrete block, or the like, is subject to the surface of the masonry or its surface due to secular change such as shaking due to an earthquake and runoff of sediment during drainage. There are gaps in the inner stuffing part, back lining part, etc.
Retaining walls are often loose or full. And
If this condition becomes severe, the masonry retaining wall may collapse or collapse. Conventionally, all such stone masonry retaining walls have been reconstructed after being dismantled. However, there is a problem in the dismantling rebuilding work that it takes a long construction time and the construction cost is high, and there are also cases where dismantling is not possible due to a historical site or the like. On the other hand, there has been no example of construction work for reinforcing such a stone masonry retaining wall so as to have safety at the time of construction or higher, and no known method has been known. [0003] As a method of repairing a stone masonry retaining wall, it is conceivable to apply a usual ground improvement technique. For example, a boring machine is installed on the top of a masonry retaining wall, and a boring machine is used to drill a hole far away from the stone on the back of the masonry, and grout is squirted from the tip of the boring machine at high pressure, so that the masonry can be buried in the masonry. Inject grout into the part or the voided or hollowed part behind it,
A method to reinforce the retaining wall by backfilling the hollowed part and solidifying the surroundings of the masonry with concrete is conceivable. However, in such a construction method, the construction machine becomes large and the construction cost becomes high, and it is difficult to adjust the grout material injection pressure, so that the pressure becomes high and the masonry on the front face is pushed out or the entire masonry retaining wall is pushed down. There are various problems such as the danger, the grout material injection amount is extremely large, and the like. On the other hand, a method of driving a rock bolt from the surface of the masonry to the bedrock behind the retaining wall of the masonry and solidifying the tip thereof with the injected concrete, thereby anchoring the masonry is also conceivable. However, in this method, since the stone masonry retaining wall to be reinforced does not have integral strength, a large number of lock bolts must be used, and a lock bolt having a length of 2 to 3 m is driven. There are problems such as difficulty in securing a bolt length portion and an installation space for a machine for driving the bolt. SUMMARY OF THE INVENTION The present invention solves the problems of the prior art and the above-mentioned methods which are generally considered, and reduces the collapse and collapse of a weakened masonry retaining wall without occupying a large work space with a short construction time and a low cost and safe method. It is an object of the present invention to provide a method for reinforcing a stone masonry retaining wall that reinforces a stone masonry wall without fear of occurrence. [0007] In order to solve the above problems, the present invention provides a method for reinforcing a masonry retaining wall, comprising the steps of:
For sealing the joint of the outer surface body of the stone masonry retaining wall with the assembled outer surface body and the inner surface body behind it with a sealing material, and for injecting grout material from the surface side of the outer surface body to the interval of the inner surface body. A sealing step of providing an inlet, an injection step of injecting the grout material from the injection port, and a coring step of removing a core at the place where the grout material is injected from the surface side after the grout material is solidified. And a drainage part forming step of installing a water filter at the trace where the core has been removed. FIG. 1 is a simplified diagram showing an example of a cross-sectional structure of a masonry retaining wall, and FIG. 2 shows an example of an overall process of a masonry retaining wall reinforcing method to which the present invention is applied. . The masonry retaining wall includes a masonry 1 which is an externally mounted body, and a backing part 2 which forms a back side portion of the masonry 1 as an inner surface body behind the masonry 1 and a backing part 3 which follows. Stone 1
There are various types of stones, such as wild stones, round stones and split stones. There are stones of natural materials processed into shapes as shown in FIGS. 3 and 4 and stones of natural stones as they are. In addition, there is a stone masonry retaining wall using a concrete block manufactured in a shape as shown in FIGS. [0009] The hollow portion 2 forms a space between the stones 1 and serves to transmit the load of each stone and stabilize the stone. This portion is formed of earth and sand or chestnut stone or both in the case of an empty pile type retaining wall, and has a not-shown pillowstone which normally receives the tip portion of the pile 1. This part is filled with concrete in the piled-up retaining wall. In any case, a void or cavitation is often caused partially or entirely due to an earthquake or aging. [0010] The backfill 3 is formed of earth and sand containing raw soil and chestnut stone in an empty-stacked retaining wall. The kneading-type retaining wall is composed of a concrete wall 3a which is vertically continuous as shown by a two-dot chain line in FIG. 1 and a chestnut stone layer 3b behind it. There may be some gaps in this part due to an earthquake or the like. Behind the backfill part 3 is an original soil part 4. The masonry retaining wall is further composed of a masonry stone 1 and a crawl part 2.
Foundation concrete 5 which is the foundation of the concrete, foundation material 6 usually made of chestnut stone, top plate 7 made of concrete or mortar, chestnut stone 8 when backfill part 3 has drainage, waterproof concrete 9, its supporting chestnut 10, etc. It is composed of Such a weakened state of the retaining wall includes, as shown in FIG. 1B, loose joints 1 a of the stone 1, displacement or stagnation of the stones, the body embedment part 2 and the back embedment part 3, and further behind it. And partial hollowing of the raw soil part 4 of the above. Such a masonry retaining wall may be partially collapsed by weakening or collapsed entirely. The method for reinforcing a stone masonry retaining wall according to the present invention can be applied to a case where the masonry 1 is a natural stone or a concrete block.
Regardless of whether the retaining wall is of an empty type or of a kneaded type, and no matter what the material of the body and backfill parts, if it is a weakened stone masonry retaining wall, what kind of retaining wall can be used? It is also applicable. The method of the present invention, as shown in FIG.
The main steps include a pre-operation step A, a sealing step B, an injection step C, a coring step D, and a drainage channel forming step E performed as necessary. In the preceding work step A, the condition of the joint 1a of the stone masonry wall, the state of the cavity of the body filling part 2 and the back filling part 3, the state of the drainage pipe, the soil quality behind the back filling part 3, the inclination angle, and the height ,
Investigate the surrounding topography, etc., calculate the required amount of sealing materials, grouting materials, water filtration bodies, etc., estimate the required number of workers and machines, the construction period, etc., and determine the work place and construction schedule. The hollow state is performed using, for example, a measuring rod. Such a pre-operation step A is performed as necessary depending on the construction scale, site conditions, the request of the orderer, the presence or absence of similar construction, and the like. When the inclination angle of the masonry retaining wall is large or the retaining wall is high, a calculation for confirming the safety of the masonry retaining wall against collapse or overturning is performed from data such as soil properties, retaining wall shape, and embankment. . At the end of the preparatory work step A, weeding and the like of the masonry retaining wall are performed, the main body is checked, and the process proceeds to the subsequent substantial construction. In the sealing step B, the joints 1a between the stones 1 are closed with a sealing material. The sealing material is prepared by mixing silica-based silica sand Nos. 6 to 7 and an organic adhesive in an appropriate ratio with an inorganic high-strength cement, adding water thereto, and kneading the mixture. Usually, the final strength of 20 to 10 to 20 minutes is required.
A material is used which can obtain a strength close to the final strength in one week by obtaining about 30%. In this step, as shown in FIG. 5, the produced sealing material is formed into a lump 11 having an appropriate size, and
Then, the joint 1a is completely sealed by fitting the lower and upper surfaces of the joint 1a from below, while accomodating the front and back surfaces so as to close the joint. Since this sealing material adheres to the stones 1 on both sides and has an early strength as described above, the sealing material is integrated with the stone within a few minutes after the application and exhibits a sealing effect. Seal part 1 that closed joint 1a
The depth b in the depth direction only needs to be enough to withstand the pressure applied from behind when the grout material is pressed in,
Usually, it is about 50 mm. In the masonry retaining wall, the sealing portion is effectively exhibited because the body filling portion 2 is spread in a V-shape. By such joint reinforcement in the sealing step B, the loose or confined stone space can be narrowed and the whole can be integrated. In this sealing step B, together with the joint closing work, the filling portion 2 and the back filling portion 3 are arranged from the front side 100 of the stone 1.
An injection port 12 for injecting the grout material is provided at an interval of. As shown in FIG. 5C, during the sealing process, the inlet 12 has a large / small diameter of 50 mm / 30 mm and a length of 1 mm.
A base tube 13a, such as a base for a grout material injection hose having a diameter of about 00 mm or a PVC pipe or the like, is inserted into the joint 1a, and a sealing material is hardened along the periphery of the joint, and then removed. The installation place is a place with a large interval above a joint in one row, or a place where a stone edge near the joint is slightly cut, and the number thereof is ^{2 to} 3 places per 1 m ² . In the injection step C, a grout material is injected from the injection port 12. As the grout material, a material having good basic physical properties such as solidification time, strength and days of strength generation, etc., is appropriately selected from commercially available materials. In this step, first, water specified for the grout material is added and kneaded with a mixer, and a pump is used. As shown in FIG. The grout material is discharged from the inlet 12 by driving the pump. As a pump, the maximum pressure is 5-10kgf /
A low pressure of about ² cm may be used, and an electric pump or the like may be used, but it is often better to use a manual pump. That is, the body filling portion 2 and the back filling portion 3 of the masonry retaining wall.
Since the cavity volume and gap in, there is considerable variation between each retaining wall of the construction object and each location of the retaining wall even in the same construction, in order to ensure that grout material is injected and completely spread to the gap, This is because it is desirable to drive the pump with human power and press-fit it while adjusting the power according to the magnitude of the driving force, that is, the response. It is desirable that the pump, grout material tank, and the like be installed at the top end of the masonry retaining wall if space is available. If you do so, hose 14
And the head pressure of the grout material can be applied to the inlet 12. Reference numeral 15 in FIG. 6 is a temporary support for the hose. The grout material is injected sequentially from the lower stage to the upper stage of the stone masonry retaining wall. At this time,
The connection between the base 13 of the hose 14 and the inlet 12 is sequentially changed. When the stone masonry retaining wall is long or the like, the plurality of inlets 12 at the same level may be simultaneously injected in parallel with a plurality of hoses at intervals of, for example, two pitches. When the grout material is injected into one injection port 12, the grout material usually flows out from another injection port 12 close to this, and the injection into that port is terminated at that point. If the pressure of the pump is increased without this outflow, it is determined that there is no gap in the casing 2 and the like. Plug and seal the mouth. In FIG. 6, the flow state of such a grout material is indicated by arrows. That is, the grout material injected into one stuffing part 2 first fills the hollow part in the stuffing part 2 if there is a cavity. Because there is a porosity of about 30%,
It penetrates into the void portion and turns the entire stuffing portion 2 into concrete, and furthermore, the left and right and upper and lower neighboring stuffing portions and backing portions 3
Also partially invades. Then, as described above, when the grout material injected from one port comes out of the neighboring injection port 12, the injection from one port is terminated. When such grout material is solidified after injection, the stone 1 shown in FIG.
Neighboring stones 1 including (1-1) and 1 (1-2) are penetrated into the backfilling part of the grout material, which is partially formed as shown by the two-dot chain line in the figure. By virtue of this, they are firmly integrated. When the backfilling portion 3 is made of the rubble stone 8 for draining water as shown by the two-dot chain line in FIG. 1, since the grout material has good permeability, it flows largely into the rubble stone side to block the water passage. Since there is a possibility, the grout material is injected from the injection port 12 at a low pressure so that the grout material can sufficiently spread over the entire hollow portion 2. When there is no rubble stone for backfill drainage like a Nozumi retaining wall, press-fit while maintaining a relatively high pressure close to the upper limit pressure. In the core removing step D, as shown in FIG. 7A, after the grout material is solidified, the core 16 where the grout material is injected is removed from the surface 100 side by using a drilling machine. The core 16 has a ratio of about 1 per 2-3 m ² ,
A diameter of about 0 mm and a gradient of about 1/100 are applied to make the length about 450 mm. This length varies depending on the size of the hollow portion 2, that is, the size of the stone 1, but if the length is about 450 mm, it usually passes through the hollow portion 2. Core 16
In order to make a sample of the grout material injection part, it is water-cured so as to have strength by covering it with a wet cloth, etc., and is subjected to a 4-week strength test which is a standard test method of grout material, and its compressive strength is measured. Is done. Further, the state of the trace of grout material injection appearing on the surface of the core 16 is visually inspected. By such an inspection, it is confirmed that the retaining wall integrated with the stone 1 that is solidified with the grout material and has the safety against the crushability and the collapse property. In the drainage part forming step E, the core 1
The water filter 17 is set in the empty space 16a from which 6 has been removed. In this example, the water filter body 17 is composed of an outer cylinder 17a made of a PVC pipe having a diameter of 75 mm and opened at both ends and having a number of holes (not shown) formed in a cylindrical portion, and a cylindrical special filter 17b inserted therein. It is composed of The outer cylinder 17a is partially fixed with mortar in the core vacant space 16a. The special filter 17b is composed of a cylindrical body in which a polypropylene network-forming pipe forming the inner and outer surfaces is combined with a polyethylene terephthal fiber filler therebetween. In the conventional draining method in which a PVC pipe is filled with a normal filter, when mud or silt-based wastewater is treated, the filter becomes clogged and cannot be drained in a short period of time. It absorbs and drains water, and does not clog semipermanently. This allows
Drain rainwater that has permeated the backfill part without fail, and joint 1
Even if a is sealed, the collapse and collapse of the stone masonry retaining wall due to water can be reliably prevented. According to the method for reinforcing a stone masonry retaining wall as described above,
With a low-cost, safe construction method with a short construction period, the weakened masonry retaining wall can be reinforced so that it does not collapse or collapse. In this case, since there is no need to use a large-sized machine, the work can be performed at any site without occupying a large work space. In addition, according to the method of the present invention, at least the masonry and the hollow portion are integrated, and when these are fixed with the lock bolts, the retaining wall strength can be further increased by a small number of bolts. A synergistic effect occurs. As described above, according to the present invention, the joint of the outer surface of the stone masonry retaining wall having the assembled outer surface and the inner surface behind the seal is closed with the sealing material by the sealing step. Since the grout material is injected from the surface of the outer body to the space between the inner body and the grout material, the grout material is injected from the inlet in the injection process. With this, the grout material can be directly injected into the inner surface portion. Therefore, when there is a hollow portion in the inner surface body portion, the hollow portion can be easily filled with the grout material at a low pressure from the near side to the deep side of the hollow portion. And it can prevent that the high pressure which collapses the outer surface body of a stone masonry wall from inside from this is prevented. As a result, the grout material can be safely injected. In other words, according to the method for reinforcing a stone masonry retaining wall, the grout material is easily and safely and securely packed with the inner surface of the masonry masonry wall easily and securely using the characteristic that the inner surface of the masonry masonry wall extends from outside to inside. Can be. When the grout material is filled in the hollow portion of the inner body having the inlet, the grout material penetrates into the void portion in the inner body made of earth and sand, and also enters the hollow portion of the adjacent inner body. go. Then, by injecting such a grout material from injection ports at a plurality of appropriate positions, the entire masonry retaining wall including the whole or a part of the outer body and the inner body can be integrated. Next, in the coring step, after the grout material is solidified, the core where the grout material is injected is removed from the surface side, and it is checked whether the solidified grout material has the necessary strength. Then, the reinforcing effect of the stone retaining wall can be confirmed. In addition, since the water filter is installed at the trace where the core was removed by the drainage part forming process, both the strength inspection and the drainage part formation were achieved without the core, and the method of reinforcing the stone masonry retaining wall was improved. can do. Further, since the water in the inner body can be reliably drained to the surface of the outer body by the water filter, even if the joint is sealed, there is no danger of collapse or collapse due to the water being contained in the stone masonry retaining wall. As described above, according to the method of the present invention, the grout material can be sequentially packed at a low pressure from the near side of the inner body at the outside. The high pressure applied to the body does not cause the masonry retaining wall to collapse and the reinforcement work can be performed safely. In addition, since only necessary parts are converted into concrete centering on the hollowed parts, efficient reinforcement work can be performed, and the construction period can be shortened. In particular, the construction period can be significantly reduced as compared with the conventional construction of rebuilding a stone masonry retaining wall.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing a structural example of a stone masonry retaining wall to which the present invention can be applied, wherein (a) shows a cross-sectional state and (b) shows a partial planar state. FIG. 2 is an explanatory view showing a process example of a method for reinforcing a masonry retaining wall to which the present invention is applied. 3A and 3B show examples of the shape of a stone used for the stone retaining wall, wherein FIG. 3A is a side view and FIG. 3B is a front view. 4A and 4B show another example of the shape of the stone, wherein FIG. 4A is a side view and FIG. 4B is a front view. FIGS. 5A and 5B are explanatory views showing an example of a sealing step, wherein FIG. 5A is a front view when a sealing material is applied to joints, FIG. 5B is a cross-sectional state of the sealing material, and FIG. (D) shows a cross-sectional state where the injection port is formed. FIG. 6 is an explanatory view showing a state in which a grout material is injected and a state in which the grout material enters. FIGS. 7A and 7B show a coring and drainage section, wherein FIG. 7A is a cross-sectional view of a coring portion, FIG. 7B is a cross-sectional view showing an installed state of a water filter, and FIG. . [Explanation of Signs] 1 Stone (external body) 1a Joint 2 Filling part (internal body) 3 Backfilling part (internal body) 12 Injection port 16 Core 16a Empty trace (removed core) 17 Water filter body 100 Surface B Sealing process C Injecting process D Coring process E Drainage part forming process

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-10-252084 (JP, A) JP-A-9-256393 (JP, A) Registered utility model 3032570 (JP, U) (58) Fields surveyed ( Int.Cl. ⁷ , DB name) E02D 29/02

Claims (1)

(57) [Claims 1] A joint of the outer surface body of a stone masonry retaining wall having an assembled outer surface body and an inner surface body behind the outer surface body is closed with a sealing material, and a front side of the outer surface body is provided. A sealing step of providing an injection port for injecting the grout material into the gap between the inner surface bodies, an injection step of injecting the grout material from the injection port, and the grout from the front side after the grout material is solidified. A method for reinforcing a masonry retaining wall, comprising: a core removing step of removing a core at a location where a material is injected; and a drainage part forming step of installing a water filter at a trace where the core has been removed.