機場捷運CEO2 施工標山鼻站（A10）基礎設計型式為擴展式基礎，由於基礎下之地質軟弱，恐有受水浮力及土壤液化現象產生，導致基礎下陷，進而影響結構體安全之疑慮，經設計檢討採高壓噴射灌漿 JSG 工法施作地盤改良予以防止。改良範圍以山鼻站柱位共計4處（25支／處）配置改良，而本工程之施作完成後，除有前述效果外並能增加土壤摩擦力，可有效提供結構承載，防止載重過量或不均勻，致壓密沉陷之狀況發生。
The foundation design of TIAA MRT Shanbi Station (A10), CE02 Tender, adopted the extended foundation. Due to soft geological conditions that may cause water buoyancy and soil liquefaction, leading to subsidence and further affecting the safety of structures, the high-pressure JSG (Jumbo Jet Special Grouting) method was applied to improve the foundation and prevent such problems. The improvement scope included 4 sites (25 piles per site) in Shanbi Station. After the completion of this construction, it is estimated to present the abovementioned effects and also increase soil friction. The improvement could effectively provide the structural resistance to prevent overloading or uneven load that may result in consolidation subsidence situation.
The construction of JSG piles used a drill pipe equipped with a super-hard nozzle and air nozzle at the front end to drill into the soil to a predetermined depth so the high pressure hardening material will rotate within the foundation along with the surrounding air. The rotations will cut the foundation and air convection will lift the slime out of the ground. At the same time, the soil will be transformed into a solid form that is forcibly mixed by soil and cement slurry.
The advantage of high-pressure JSG method is flexible depth handling which can apply hardening materials according to the actual improvement scope in uneven soil layers so as to achieve the desired depth of soil improvement effect. The soil improved by this method has excellent soil strength and water-intercept ability, public hazard-free and noise hazard-free. The hardeners used are mainly cement which will not dissolve in water after hardening, so will not pollute the groundwater. Utilizing this kind of material also prevents vibration and noise during construction so that the method is one of the excellent options for foundation improvement.