ABSTRACT:

In order to develop the system for the analysis of seepage flow in jointed rock masses, the authors have carried out several in-situ tests and examined the system we have developed. In this system, seepage flow is analyzed with a joint network model in which the joints are distributed statistically. In this study we newly carry out in-situ test which the objection is radial flow, and we apply the system to the test.

RESUME:

Pour developper Ie systeme pour I' analyse du ecoulement suintant dans des roches jointes, I' auteur a execute plusieurs examens in situ et examine Ie systeme que nous avons developpe. Dans ce systeme, l'ecoulement suintant dans des roches jointes est analyse par un modele du reseau des fentes, dans lequel les fentes sont distribuees statistiquement. Dans cette etude, nous executons a nouveau un examen in situ dans lequel nous avons pour objet I'ecoulernent radiale, et nous appliquons Ie systeme a I'examen.

ZUSAMMENFASSUNG:

Fur die Entwickelung des Systems fur die Analyse von der durchsickernsflut in der spaltigen Gesteinsmechanik, hat die Autor einzelnen In situ-Test ausgefuhren, und das System, das wir entwickelt haben, gepruft. In diesem system, wird die Durchsickernsflut mit spaltigem Modell des Sendernetzes, in dem die Spalten statistisch ausgeschuttet werden. analysiert. In dieser Studie, verwirklichen wir. In situ-Test, dessen Hauptziel radiale Flut ist. Wir anbringen das System gegen den Test.

1 INTRODUCTION

In order to develop the system for the analysis of see page flow in jointed rock masses, the authors had carried out several in-situ tests and examined the system we have developed. In this study, in-situ experiment has been also carried out and we examine this system. Permeability of hard rock masses is strongly affected by rock joints. In this system, based on this view, seepage flow is analyzed using a joint network model in which the disk-shaped joints are distributed. The results we obtained in the past tests using this system had a good correspondence to the measured values. In the past tests, the subject of investigation was linear flow in joints. Thus, in this study, the authors carried out in-situ test concerning radial flow similar to Lugeon test as shown in Figure 1, and apply this system to the simulation of the test. In addition, we observed the joints in boreholes using BTV and used them for analysis effectively.

2 SURVEYS AND TEST
2.1 Preliminary investigation

Before carrying out the permeability test, the following preparation and investigation have been done;

2.1.1 Surface cutting of the test site

The test site is composed of Cretaceous granites. Rubble and top soil on the test site were removed, and fresh rock masses were excavated until almost ground water level. Size of the test site is 7 by 7 meter (see Figure 2).

2.1.2 Joint survey Strike

dip, length and aperture of joints which trace length is larger than 30cm on the surface of the test site were measured using scan window survey methods.

2.1.3 Construction of cap concrete

Rock surface were covered with concrete (cap concrete). Figure 2 and Figure 3 show the horizontal view and the cross-section of the test site, respectively. 5m by 5m cap concrete (thickness is 50cm) were constructed in order to stipulate non-permeable boundary and 1m width trench is established around the cap concrete which is surrounded by the concrete in order to regulate the water level of this site.

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