• Journal of the Korean GEO-environmental Society
• /
• v.10 no.2
• /
• pp.45-50
• /
• 2009

The differential settlement may be generated by the variation of stresses caused by the soft ground or ground water. The cracks are usually created when the structures are leaned or deformed due to the differential settlement. A grouting method has been mainly used till now to improve the bearing capacity of the ground when the foundation of the structure is deformed by differential settlements. However, when this method is used, it takes too long time to obtain the required strength and the period of the reinforcement effect is not long enough. The advantage of GPCON injection method is to have good mechanical properties and durability, and easy construction. In addition, the GPCON method rapidly fills up the void in soils by injecting some materials into underground and also obtain the increase of bearing and shearing forces due to the expansion. In this paper the restoration capability of the foundation settlement of railway and subway subjected to cyclic loading is analytically and experimentally evaluated using the high density rapidly expansion GPCON in order to investigate the types of deformations and vibrational characteristics.

• The Journal of Engineering Geology
• /
• v.30 no.2
• /
• pp.185-198
• /
• 2020

High-density rapid expansion material is a method that increases the solid volume of injection materials due to hydration and foam reactions at the same time as spraying. It is an effective method for securing ground stability, restoring subsidence, and loading during construction of structures. In this regard, through the mechanical experiments of injection materials, the stability of the foundation ground of the structure and the effect of increasing the endurance using site construction were analyzed. The results of the experiment showed that the unit weight of soil decreased by 10.5% after injection of the filling material, and the allowable support for the structure was deemed safe, and the subsidence by each section after ground improvement was determined to be safe at 2.28, 1.55 and 0.46 cm, respectively, with an acceptable subsidence of less than 5 cm. After the field test, five inclinometers were installed on the top floor of the target building to measure the displacement of the X and Y axes. As a result of the measurement, no displacement related to the phenomenon of inequality or subsidence cracks of the structure was measured for about 16 months (509 days) after construction. This can be judged to be a sufficient increase in the stability of the ground after the injection of rapid expansion.

• Journal of the Korean Geosynthetics Society
• /
• v.7 no.2
• /
• pp.1-5
• /
• 2008

The differential settlement on ordinary concrete buildings and paved roads are often occurred and which caused the failure of structure. The grouting method can be used for correcting the settlement of the structure. However, the grouting method has a disadvantage like that it takes a long time period to get a desired strength, and it is not a continuous in the phase of reinforced effect. In this paper, as an injecting material called GPCON to complement disadvantage, it is estimated about the characteristic that has a high-density expansion. With the changing of ground conditions and amount of injection, the change of physical strength on compression, the stability against chemical material are studied through the filming of SEM. The physical strength with compression is developed to high strength due to mixing with other material. It is not react with most of the material on chemical conditions except the component of alcohol. Through the SEM test. it is confirmed that the strength of material was increased as formation is being densified.