Field Experimental Study on Mechanical Properties of Frame Support Structure Composed of Subway Foundation Pit Retaining Pile and Steel Strut Rigid Joint

Table 1

Statistics of key time nodes in the experiment.

Time node		Experimental phase
December 25th	11 : 56	Excavate the first layer of soil
	15 : 13	Install the first layer of steel strut
	15 : 35	Excavate the second layer of soil
	17 : 28	Install the second layer of steel strut
	17 : 57	Excavation to the bottom of foundation pit
December 26th	16 : 00 to 18 : 00	First loading
December 27th	9 : 00 to 13 : 00	Second loading
	15 : 00	Connect the water pipe to the water pump and start water injection
	15 : 45	End of water injection
	16 : 15	Start removing the inner strut
	16 : 19	Strut removal completed