Through collecting 76 groups of the in-situ stress data in underground water-sealed storage cavern in Chinese mainland

including Zhanjiang

Huangdao

Yantai

Huizhou

Jinzhou

Dalian

the distribution of the vertical stress，the largest horizontal principal stress( )

the minimum horizontal principal stress( ) and the lateral pressure coefficient(k) varying with depth in Chinese mainland are established. Then the features of the in-situ stress are corresponding regression analysed refer to the analysis method of Hoek and Brown. The results indicate that: (1) The shallow in-situ stress in underground water-sealed storage cavern in Chinese mainland show increasing trend with the increase of depth

showed a good linear relationship with depth

and the stress gradient is a little less than 0.027

in Hoek-Brown relation. (2) and are increased with depth

scattered points are mainly distributed in an inclined parallel belt. (3) Lateral pressure ratio k is dispersed when depth is less than 200 m

and centralized when depth is more than 200 m

and the envelope curve of lateral pressure ratio is distributed between the maximum and minimum envelopes of Hoek-Brown curve; it is approach the global distribution law. Through above research

the distribution law of in-situ stress field in underground water-sealed storage cavern in Chinese mainland is analyzed and summarized; it can provide references to the planning

constructing and developing of petroleum (gas) strategic reserve in Chinese mainland.