More and more transmission lines pass through the desert area covered by aeolian sand

and steel grillage foundation has good applicability

but there are few field tests at present. In Yulin area of Shaanxi Province

southern edge of Maowusu sandy land

several groups of full-scale uplift tests of steel grillage foundation in aeolian sand ground were carried out

and the uplift bearing capacity

uplift and surface displacement

support and floor stress

upper earth pressure and other parameters were tested and analyzed. The results show that the uplift load-displacement curve of the steel grilage foundation is similar to that of the spread foundation

which can be divided into the approximate straight section

plastic transition section and linear instability section. When the cumulative uplift displacement reaches 21-23 mm

the foundation comes to the limit state. If small cracks appear on the ground surface around the top of the foundation during loading and propagate along the diagonal direction

the foundation will enter the limit state under the next level load. By analyzing the variation characteristics of the earth pressure on the upper part of the foundation

the fracture point on the uplift fracture surface of the foundation can be found

and the actual uplift angle can be calculated. The uplift bearing capacity calculated by the soil weight method in the existing codes is larger than the test value of ultimate uplift bearing capacity. It is suggested that the uplift angle should be 19.0o to 19.5o in the foundation design of relevant areas.