JPS61186624A - Sliding preventing device for retaining wall - Google Patents

Abstract

PURPOSE:To increase the sliding resistance force of a whole retaining wall, where necessary, by a method wherein an auxiliary plate is horizontally positioned to the end surface of the bottom plate of the retaining wall, and the bottom plate and an auxiliary plate are intercoupled by means of a wire. CONSTITUTION:After a retaining wall A is built on a foundation concrete 7, an auxiliary plate 1 is installed in the direction of an earth pressure and horizontally to an end surface 2a of a bottom plate 2 of a retaining wall A. After the bottom plate 2 and an auxiliary plate 1 are intercoupled by means of a pin 3 and a wire 4, filling with soil D is effected. This enables increase of a sliding resistance force only at a necessary place, and permits building of the retaining wall which has increased efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a retaining wall slip prevention device for resisting sliding due to earth pressure.

(Problem to be Solved by the Invention) In a projecting type retaining wall such as an L-shaped retaining wall, sliding is mainly resisted by frictional force on the bottom surface, so its design, especially the length of the bottom plate, must be carefully considered against sliding. It is determined.

The bottom slab of a retaining wall is designed to satisfy all the conditions for ground support and stability against overturning and sliding, but the former usually has more margin in terms of safety against overturning and sliding than the allowable value. As mentioned above, the design is based on the degree of safety against sliding.

Therefore, if the design of the retaining wall, especially the length of the bottom plate, is determined based on the degree of safety against sliding, the degree of safety against overturning becomes large, making it difficult to design economically. If the degree of safety against sliding does not meet the allowable value, a method is sometimes adopted in which a protrusion is installed on the bottom surface to expect passive earth pressure. Since this is a common practice, the method of providing protrusions does not suit the actual situation.

This invention was made based on these circumstances, and attempts to design an economical retaining wall by determining the length of the bottom plate based on the degree of safety against overturning.

(Another Means to Solve the Problem) In order to make the retaining wall economical in shape, the length of the bottom plate in the present invention is determined so as to satisfy the degree of safety against overturning. When considering sliding with the length of the bottom plate determined in this manner, the sliding resistance force is insufficient, so an auxiliary plate is connected to the bottom plate to compensate for the insufficient frictional force. The auxiliary plate is attached mainly to resist sliding, and since frictional force acts on at least the top and bottom surfaces of the auxiliary plate, a small size is sufficient.

In addition, the auxiliary plate is integrally connected to the bottom plate in the earth pressure direction,
Effectively increases sliding resistance.

(Example) The present invention will be described below along with an illustrated embodiment.

This retaining wall slip prevention device uses the auxiliary plate 1 as the bottom plate 2 of the retaining wall A.
The auxiliary plate 1 and the retaining wall A are connected in the earth pressure direction to the end face 2a of the retaining wall A, and the auxiliary plate 1 is configured to be integrated with the retaining wall A, so that the auxiliary plate 1 compensates for the lack of sliding resistance.

Note that the number of auxiliary plates 1 to be connected is not limited to one. Figures 1 to 3 show an auxiliary plate 1 having the same thickness as the bottom plate 2, with a slight gap between it and the bottom plate 2. and a bottle 3. on the bottom plate 2. This is a case where the wires 4 or the like are connected by pin connection. In this case, since the auxiliary plate 1 is pin-jointed, it is not affected by the overturning moment, and only frictional force acts on both the upper and lower surfaces.

The stability calculation for retaining wall A at this time is as follows.

In Fig. 4, if the earth pressure coefficient is C2 and the unit volume weight of soil is W, the earth pressure P acting on the front wall of retaining wall A is P = 172wCH2, and the safety level Fos against falling is Fos = (w, l , +W212) /P h, and the length of the bottom plate 2 is determined by satisfying Fos ) 1.5.

On the other hand, the frictional force F1 of the retaining wall A, that is, the bottom plate 2, is the friction coefficient between the bottom surface and the foundation μ. Then F, = (W, +W,)
, μ.

The frictional force F2 of the auxiliary plate 1 is F2=(W, +W4)·μ, where the friction coefficient between the soil and the top surface of the bottom plate 2 is μm. +W4・μm. In other words, the safety level Fgs against sliding of the entire retaining wall A with the auxiliary plate 1 integrated is Fgs = ((W, +W2+W3+W4) μo+W
4μ, )/P, and this value is approximately 50 of Fl when the auxiliary plate 1 is 1/2 the area of the bottom plate 2.
% increase. That is, at this time, 1.5 F+/ in Fgs
P, and the allowable value for bottom plate 2 only is 1.5 or 2.0
Even if it is less than Fgs, it is easy to use supplementary version 1) 1.
5 or 2.0, which can reach the allowable value.

Next, the embodiment shown in FIGS. 5 and 6 is a case where an auxiliary plate 1, which is larger in size than the bottom plate 2, is rigidly joined to the bottom plate 2 by a joining plate 5, bolts 6, etc.

At this time, since the auxiliary plate 1 is rigidly connected, it resists the overturning moment, and the greater the force, the more frictional force acts on the sides.

The stability calculation at this time is roughly as follows.

The earth pressure is the same (P=1/2wCH (see Figure 7).

The safety level Fos against falling is Fos = (W, l, +W212+ (W3+W4
) (L+z3/z))/PhPhThe earth pressure p acting on the side of the auxiliary print is 1) = (1), +ρ2)/2, and the resultant force P
1 is P+=(P+ + p2) dsls/2.

The frictional force F1 acting on the bottom plate 2 is P+ = (W, + W2) μ. However, supplementary version 1
The frictional force F2 acting on is F2=(W3+W4)μo+2P1μm+W4μ, and the safety level Fgs against sliding easily exceeds the allowable value (ignoring the passive earth pressure applied to the auxiliary plate 1).
.

As we have tried to examine stability using the above two examples, even if the length of the bottom plate 2 is determined by the degree of safety against falling, and as a result, the degree of safety against sliding is insufficient, this degree of safety is determined by the auxiliary plate 1. Enough? It becomes possible to add R.

By the way, the shape and scale of the auxiliary plate 1 are not limited to those shown in the example, and can be arbitrarily adjusted in relation to the bottom plate 2 of the retaining wall A, and the retaining wall A can be manufactured by integrating the auxiliary plate 1 from the beginning. You can.

(Effects of the Invention) The present invention is as described above, and as described above, by connecting the auxiliary plate to the bottom plate, the sliding resistance of the entire retaining wall can be increased as necessary. Therefore, the length of the bottom plate can be selected as long as necessary, and as a result, the retaining wall can be designed economically, and the retaining wall can be manufactured with high efficiency.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the case where the auxiliary plate is joined to the bottom plate, and FIGS. 2 and 3 are sectional views and plan views thereof, respectively. FIG. 4 is an explanatory diagram of the stability calculation stage, and both diagrams show side views. FIG. 5 is a perspective view showing the case where the auxiliary plate is rigidly joined, and FIG. 6 is a sectional view thereof. FIG. 7 is an explanatory diagram thereof, where I and 11 show a side view, and ■ shows a plan view. A: Retaining wall, 1: Auxiliary plate, 2: Bottom plate, 2a: End face of bottom plate, 3: Bin, 4: Wire, 5: Joint plate, 6: Bolt, 7: Foundation concrete, 8: Foundation split stone. Figure 2 δ Figure 4-1 Third Do No. 4 r'l-11 Procedural Amendment Statement December 26, 1985 Patent Office 1 Dear 1. 1. Indication of the case 1985 Patent Application No. 27930 2. Name of the invention Retaining wall slip prevention device 3. Person making the amendment Relationship to the case Name of patent applicant 4. Agent 5. Date of amendment order Spontaneous amendment Showa year, month, day (shipping date) 6, number of inventions increased by the amendment 7, subject of the amendment Description: Claims 1 (1) The claims are amended as follows.

Claims (1)

[Claims] (1) A retaining wall slip prevention device characterized in that an auxiliary plate is horizontally connected to the end face of the bottom plate in the earth pressure direction, and the auxiliary plate and the retaining wall are integrally formed.