The distribution of pore water pressure along the slip surface used for the stability analysis is usually calculated from the static pressure estimated from the groundwater level. But in landslide slopes which have the multi-stratums with different permeability values, the pore water pressure can not be obtained in this way since the vertical distribution of that is not static.
In this paper a simple finite element analysis of groundwater flow with a free surface is used to determine the distribution of pore water pressure along the slip surface. The numerical results of water pressure are in good agreement with the field measurements. The stability analysis of landslide slopes using these distributions of water pressure provides the reasonable factors of safety.

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In this report, the writers examined shear characteristic of sliding surface clay and movement mechanism of re-slide type landslides through ring shear test results. Consequently, if sliding force is smaller than residual strength, transformation will not take place and strain will keep null. Because relationship between the ring shear test result (φ_r', W_L, W_p, I_p) and clay fraction is examined by multivariate analysis, φ_r' can be assumed from W_L and W_P.

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Either component or stress field classifies mass movement into creep and failure. If materials are soil, it will mean the shape of grain, its size distribution and its structure. Stress field consists of pore water pressure and grain-to-grain stress. It is about 10 years since R. J. Chandler, A. W. Skempton and S. Iwanaga presented their notable studies. It is their common results that landslide or landslip character depends on the clay content of moving mass. The threshold is between 20 and 30 percent. Under deformation, clay bears rarely variation in volume, while sand and silt keep dilatancy. Speciality of sand and silt is almost the same each other. The writer tried to show soil behavior by a grain model. That is, ball grain of sand and silt, and layer-built one of clay dominate their movement pattern.

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In this study, characteristics of landslide is considered from Remote Sensing data and DTM (Digital Terrain Model). A hill shading map, a sumit level map and a drinage pattern map were generated from DTM. A vegetation map and a landcover map were generated from LANDSAT TM as remote sensing data. From these maps, almost landslides were near an abundance of water resource which is stream or rice field. And landslide might be related with water erosion in topographical level.
We suggest to use slope stability analysis for prediction of landslide. Generally, slope stability analysis has been applied to only the area where landslide had been occurred. However, we attempt to apply it to all areas regardless of landslide occurrence. A method of landslide risk mapping has been developed with use of Remote sensing data, DTM and ground survey data of geology and soil mechanics. The proposed method will be useful for preparedness of landslide prevention in the wide and steep terrain such as SHIKOKU Island, JAPAN where landslides occurred very often.

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In planning for the pile design of landslide prevention, it is necessary to consider the pile functions effected by the landslide features such as softness of moving mass, slip surface configuration and the location of pile construction. The pile design on the present time is conducted by information based on the engineering experience.
This paper discusses an application of neural network for the pile design constructing to landslide. By use of neural network having the function of self making organization, the pile deflection amount in planning area can be easily estimated without the hardly numerical calculation. The influence degree of landslide feature against the constructed pile is also demonstrated through the actual examples.

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From Miyazaki City, to Kokubu city, Route 220 runs 183.3 kilometer, loing through Nichinan City and Shibushi. A part or “the Nichinan Coast” between Horikiri Pass in Miyazaki and Kazata in Nichinan has officially been selected as one of the “100 Japan's Roads, ” because of its scenic beauties and the panorama of the Pacific Ocean.
Constructed by means of cutting steep mountain slopes, however, Route 220 here frequently suffers landslides, which cause serious traffic damages at time.
This paper reports the outline of those landslides that occur at artificial slopes along the Nichinan Coast.
In general, they are classified into following four groups in terms of their characteristics:
1) Rockall of sandstone blocks in 5-to 15-meter layers.
2) Mortar shooting tearing off.
3) Landslide of sandstone layers accumulated on mudstone layers.
4) Surface soil slide.

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A new method of landslide depth measurement by using pressure-sensitive cable was examined at Okimi landslide in Niigata prefecture.
In pressure-sensitive cable, reflected wave is generated not only at the end point but also pressed point.
When the terminated impedance is smaller than it's characteristic impedance, reflected wave has negative polarity against the incident wave.
Pulse generator with constant interval output and digital sampling cathode ray oscilloscope are used as the measurement instruments.
Because the traveling velocity of the pulse in the cable is constant, the time interval between the incident wave and the reflected wave is proportional to the cable length.
And subtracting the constant offset of cable length, the depth of landslide was detected at the landslide displacement of 20mm and the depth was 23.2m.

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