Study and Application of Low Pressure Grouting Method to Surround and filling Liquefied site

• Main Authors: Zhang, YI-CHI, 鄭譯馳
• Other Authors: Sheen MAU-SONG
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/upm629

碩士 === 國立高雄應用科技大學 === 土木工程與防災科技研究所 === 106 === The sandy soil with high relative density is not easy to liquefy, enforce to make the soil particles of sandy soils have no relative displacement under earthquake and will not liquefy. 　　In this study, we used the United States Syntron company relative density instrument shaker, and 60cm * 60cm * 45cm thick 0.5cm thick glass tank to conduct test in liquefaction. A model sand tank with a uniform grading of white standard sand and a finely-graded black Ligang sand is used to simulate a soil liquefaction environment. 　　Conducting two types of anti-liquefaction site improvements, one is the independent base foot and the raft foundation model. Under the external bamboo pile, the relative density of the sandy soil under the foundation is used to resist the earthquake. The other is to fill the sandy soil below the range of grouting consolidation with low-pressure filling. Make the sandy soil particles have no relative displacement under earthquake to improve the anti-liquefaction ability of the site. through relative density shaker test, Make the original Liquefied site improved to a non-liquefied site. Among them, the best anti-liquefaction effect is the Surround type low pressure grouting with a 100% improvement rate. After the model test showed that the site could not be liquefied under earthquake for 3 days. If the foundation is made of plum type improved pile is consolidated, the improvement rate is less than 100%, and the soil particles still liquefed under the earthquake. 　　The relative density of the liquefied soil below the footing is added to the additional pile to the relative density that is less prone to liquefaction. However, it liquefies when the soil next to it earthquakes, excess pore water pressure softens the soil between piles due to liquefaction penetration improvement zone. Caused the base foot skew and subsidence of the foundation pile, therefore, the piles resistant to liquefaction must still penetrate into the hard soil layer of the non-liquefaction zone, and designed with point piles. 　　The surrounding type low-pressure grout has an impatience of pulp and bubbles between the foundation of the sky-permeable building and the surface of the soil, and may cause a slip of the slip between the building and the soil under earthquake. Therefore, it is recommended to insert rail piles to increase the connection between soil and buildings in the surrounding type grouting area to ensure the safety of buildings under earthquake liquefaction.