BOX FOR STORING DRILL CORE SAMPLES IN WHICH PARTITIONS ARE ADJUSTABLY SECURED BY FIXING UNITS CROSS-REFERENCE TO RELATED PATENT APPLICATION This application claims the benefit of Korean Patent Application No. 10-2009-0097292, filed on October 13, 2009, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a box for storing drill core samples, in which a partition is adjusted by fixing units, and more particularly, to a box for storing drill core samples collected through a borehole drilled in the ground or rocks, comprising: a receptacle with a plurality of walls; a plurality of partitions for dividing the inside space of the receptacle into compartments for receiving the drill core samples; and a plurality of fixing units for securing the partitions to the walls such that the partitions are adjusted to permit the sizing of the drill core sample receiving compartment to be changed to accommodate different sized drill core samples. Therefore, unlike the conventional art, the present invention prevents the core samples from being shaken and damaged in the receptacle when the box storing the core samples needs to be moved or the core samples need to be stored for a long time, thereby increasing storage safety. Further, in the conventional art, since the partitions are fixed in a single predetermined size not movable in the receptacle which makes the storage compartments, a plurality of boxes with different-size storage compartments are 1 needed, increasing the costs for investigation and testing. However, in the present invention, since the partitions may be adjustably fitted into the receptacle to make different-size storage compartments according to the size of the core sample, the costs are reduced. 2. Description of the Related Art Generally, when a borehole is drilled in the ground, a ground sampling process of soil and rock, among others, is necessarily and in advance performed to determine the parameters required for a construction design. This drilling investigation must be performed to get various geological stratum data, such as physical and chemical properties and stratified earth structures, among others, of the ground upon which construction of a structure will take place. Considering the present state of the ground drilling in the Republic of Korea, a lot of money is budgeted to safely store the collected samples for observation. However, the conventional separate steel split is used, an observer cannot touch or move the rock core samples which may be collected from an efflorescent rocky area or a very discontinuous fault area and therefore easily broken when the samples are held in a core storage box. To make the geologic column, when an observer observes such samples R by using a box for storing core samples as shown in FIG. 1, the observer can observe the samples R only within about a 160 degree area of the top of each sample R, which is not covered by each partition 2 dividing a receptacle 1 into storage compartments 3. In other words, since it is impossible to turn over the samples R for observation, it is difficult to observe about a 200 degree area of the bottom of each sample R. Therefore, the results of the observation are deduced from the observer's approximate assumption and thus the reliability thereof may be limited. 2 Moreover, the samples R are moved to be placed in the storage compartments 3 of the receptacle 1, so that the samples R are stored in the box. FIG. 1 illustrates the rock samples R which have been placed into the receptacle 1 for storage. During the process for a worker/observer to move the samples R into the storage compartments 3, not only the worker/observer's carefulness or effort is of paramount importance but also the samples R are likely to be deformed in most cases. Consequently, it would be impossible to accurately evaluate the properties of the relevant geological stratum, based on the stratigraphical evaluation data using the deformed samples, and therefore the reliability of the evaluation would be decreased. As described above, in the conventional art, when collecting samples from clastic rocks, first agitation occurs in the process of collecting the samples and second agitation occurs when the samples are moved from the split to the box. Furthermore, when the box for storing the rock samples is shaken or impacted while it is transferred from the drilling field to the storage place of the rock samples, more serious agitation may occur, so that the samples are likely to be damaged. Even if core samples are collected from homogenous rocks and thus in a good condition, a worker may cut the samples by arbitrarily applying an impact to the samples, to place the samples in the storage compartments (in a predetermined length/size) in the box. In this case, since it is difficult to distinguish the artificially cut surface from the naturally cut surface, a considerable error may occur in a Rock Quality Designation (RQD) value [(sum of length of cores greater than 10cm divided by, generally, 1m-standard length core obtained by N-size core boring) X 100%] or Rock Mass Rating (RMR) value, among the data to evaluate the conditions of the base rocks. 3 SUMMARY OF THE INVENTION To solve the above problems of the conventional art, it is therefore an object of the present invention to provide a box for storing drill core samples in which a partition is adjusted by fixing units, comprising: a receptacle with a plurality of walls; a plurality of partitions for dividing the inside space of the receptacle into compartments for receiving the drill core samples; and a plurality of fixing units for securing the partitions to the walls such that the partitions are adjusted to permit the sizing of the drill core sample receiving compartment to be changed to accommodate different sized drill core samples. Therefore, unlike the conventional art, the present invention prevents the core samples from being shaken and damaged in the receptacle when the box storing the core samples needs to be moved or the core samples need to be stored for a long time, thereby increasing storage safety. Further, in the conventional art, since the partitions are fixed in a single predetermined size not movable in the receptacle which makes the storage compartments, a plurality of boxes with different-size storage compartments are needed, increasing the costs for investigation and testing. However, in the present invention, since the partitions may be adjustably fitted into the receptacle to make different-size storage compartments according to the size of the core sample, the costs are reduced. In accordance with an exemplary embodiment of the present invention, there is provided a box for storing drill core samples collected through a borehole drilled in the ground or rocks, in which a partition is adjusted by fixing units, comprising: a receptacle with a plurality of walls, for safely containing the core samples for storage and movement; a plurality of partitions to be installed in the receptacle , for dividing 4 the inside space of the receptacle into compartments, according to the respective size of each of the core samples; and a plurality of fixing units for securing the partitions to the walls. BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. 1 is a perspective view illustrating a conventional box for storing drill core samples; FIG. 2 is a schematic view illustrating a box for storing drill core samples in which partitions are adjustably secured by fixing units, according to an exemplary embodiment of the present invention; and FIG. 3 is a perspective view illustrating the box for storing drill core samples of FIG. 2. [Brief description of reference numbers of major elements] 10: receptacle 11: wall 12: adjustment groove 13: storage compartment 20: partition 21: fixing unit receiving opening 22: fixing unit 30: box for storing core samples DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the 5 invention are shown. It will be understood that words or terms used in the specification and claims shall not be interpreted as the meaning defined in commonly used dictionaries. It will be further understood that the words or terms should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the technical idea of the invention, based on the principle that an inventor may properly define the meaning of the words or terms to best explain the invention. Accordingly, while example embodiments of the present invention are capable of various modifications and alternative forms, embodiments of the present invention are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit example embodiments of the invention to the particular forms disclosed, but on the contrary, example embodiments of the invention are to cover all modifications, equivalents, and alternatives falling within the scope of the invention. FIG. 2 is a schematic view illustrating a box 30 for storing drill core samples R in which partitions are adjustably secured by fixing units, according to an exemplary embodiment of the present invention; and FIG. 3 is a perspective view illustrating the box 30 for storing the drill core samples R of FIG. 2. As illustrated in FIGS. 2 and 3, the box 30 for storing the drill core sample R, in which partitions are adjustably secured by fixing units, comprises. a receptacle 10 for storing the core samples R collected through a borehole drilled in the ground and rocks; partitions 20; and fixing units 22. The receptacle 10 receiving the core samples R securely stores the core samples R, to be safely and easily moved to a research institute or a place needing the core samples R or to be safely stored for a long time. 6 The receptacle 10 comprises: a rectangular support base; and walls 11 to be installed vertically, along the perimeter of the support base (i.e., at four directions of the support base), for protecting the core samples R placed on the support base. The walls 11 are integrally connected to one another at each end of each wall 11, to be formed in a single body. A pair of the opposite walls 11 includes adjustment grooves 12. The adjustment grooves 12 permit the partitions 20 to be adjustably secured to the walls 11 by using the fixing units 22. The adjustment grooves 12 are formed in a horizontal single line on the walls 11, so that the partitions 20 are horizontally adjusted according to the size of each of the core samples R. The adjustment grooves 12 may be formed in one pair or two pairs of the opposite walls 11. The adjustment grooves 12 may vary according to the size of each of the core samples R and the height/length of the partitions 20. To install each of the partitions 20 in the receptacle 10, each of the fixing units 22 passes from the outer side of each of the opposite walls 11, through each of the adjustment grooves 12 to be inserted into the each partition 20 thereby securing the partition 20 to the walls 11. This permits the sizing of each of storage compartments 13 to be changed to accommodate different sized drill core samples in the receptacle 10. Each of the partitions 20 is in a rectangular form. To be installed in the receptacle 10, both opposite ends of the each partition 20 are respectively in contact with the inner sides of the opposite walls 11 of the receptacle 10. Fixing unit receiving openings 21 are formed on the opposite sides of the each partition 20. The fixing unit receiving openings 21 are formed to be positioned at the same line of the adjustment grooves 12 on the opposite walls 11. Each of the fixing unit 7 receiving opening 21 includes a female screw thread formed around the inner circumference surface of the each fixing unit receiving opening 21, to be engaged with each fixing unit 22. The partitions 20 are adjustably movable, along the adjustment grooves 12, according to the different size (circumference) of each of the core samples R. The partitions 20 adjusted in this manner are installed to secure the core samples R. Therefore, the core samples R are secured in the receptacle 10, thereby preventing the core samples R from being damaged during movement and long-term storage. The fixing units 22 are bolts, such as wing bolts, among others. The each fixing unit 22 passes from the outside (the outer side) of each of the opposite walls 11, through the adjustment groove 12 to be screwed to engage the fixing unit receiving opening 21 of each partition 20. The each partition 20 is secured to the opposite walls 11 in the receptacle 10 by tightening the fixing units 22. On the contrary, the each partition 20 is adjustably moved, along the adjustment grooves 12, according to the respective size of each of the core samples R, by loosening the fixing units 22. When the each partition 20 is adjusted, it is secured not to move by tightening the fixing units 22. As described above, the box for storing drill core samples in which a partition is adjusted by fixing units according to the present invention, comprises: a receptacle with a plurality of walls; a plurality of partitions for dividing the inside space of the receptacle into compartments for receiving the drill core samples; and a plurality of fixing units for securing the partitions to the walls such that the partitions are adjusted to permit the sizing of the drill core sample receiving compartment to be changed to accommodate different sized drill core samples. Therefore, unlike the conventional art, the present invention prevents the core samples from being shaken 8 and damaged in the receptacle when the box storing the core samples needs to be moved or the core samples need to be stored for a long time, thereby increasing storage safety. Further, in the conventional art, since the partitions are fixed in a single predetermined size not movable in the receptacle which makes the storage compartments, a plurality of boxes with different-size storage compartments are needed, increasing the costs for investigation and testing. However, in the present invention, since the partitions may be adjustably fitted into the receptacle to make different-size storage compartments according to the size of the core sample, the costs are reduced. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. 9