The method of the seepage analysis of rainfall in the slope was developed by using the finite element method. The slice methods of the stability analysis were mutually compared . The following conclusions were derived.
The distribution of the pore pressure obtained by computation agrees with one observed in the laboratory experiment of the seepage of rainfall in the slope. The stability analysis of the slope during the seepage of rainfall becomes possible depending on the computed distributionof the pore pressures in the slope. Janbu method and modified Fellenius method are suitable for the stability analysis of the slope during the seepage of rainfall.

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Although slope stability analyses are based mainly on a circular slip surface theory, there are not a few cases in which noncircular slip surfaces should be assumed to occur. In fact, many of the landslides in Japan have occurred with noncircular slip surfaces. Even in such cases circular slip surface analyses are made because of the great difficulties involved in locating critical noncircular slip surfaces.
This paper is concerned with a numerical algorithm to identify the critical noncircular slip surface with the minimum factor of safety based on the simplified Janbu method. The algorithm combines the Janbu method with dynamic programming on the basis of Baker's successful procedure. The computer program developed have indicated through several example problems that the present method is of great practical use.

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Authors descrived here a procedure of quantitative interpretation on movement data from bubble tube tiltmeters.
Of principal component analysis using some characteristics on movement data, consequently composite magnitude can be evaluated by the first principal component score.
With a purpose of clarify the validity of two different element fractal dime nsion and cumulative ratio, we examined a simulation. As a result of comparison between culculated values and numerical values of real data, we proved that fractal dimension is to be closely related to the peculiarity of real data.

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Xray diffraction examination in Anabara Landslide has revealed clay-mineralogical differences in some samples which are megascopically same grade hydrothermal alteration.
Frequently, landslides occurs in hydrothermal alteration zone (so-called hot spring-landslide). But the relationship between hydrothermal alteration and occurence of Anabara landslide suggests that landsliding depends on high ratio of smectite in clayfraction but not on grade of hydrothermal alteration.
Xray diffraction examination is a effective method for these study and a quantitative interpretation may be worked out by Watanabe's model.

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In case of landslide investigations, a confirmation of existing depth of slide surface is one of the most essential investigation. For the purpose of pipe-strain gauges are usually used in the most landslide areas in Japan. On the basis of these observational results, the existing depth of slide surface is definited and these data are presented for planning and designing landslide preventive works. However, recently we have been able to see many column diagrams of strain variation which have some unreasonable measured results of those pipe-strain gauges.
Thereupon, on the basis of these observational examples, we carried out comparison between the measured results of these pipe-strain gauges and geological column, and measured results by inserting-type-strain meter, examination of the insulation resistance of the circuit including pipe-strain gauges and lead wires, and measurement of the resistance of each strain gauge. Further, we considered causes why such unseasonable column diagrams of strain variation were obtained.
As a result of these examinations, the main causes of such unreasonable columns are as follows:
1) Scratch or disconnection of lead wires and treatment parts of waterproof and dampproofing of strain gauges when inserting a pipe-strain gauge into a borehole or when pulling out a casing pipe from a borehole.
2) Deteriorative phenomena of insulation resistance of lead wires and treatment parts of gauges for a long time.
3) Abrasion phenomena of strain gauges from vinyl chloride pipe for long time.

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