Abstract: With the constant development of mining and other geotechnical engineering，more and more underground engineering will relate to the design，construction and maintenance of the close laneways.Deformation and failure law of the covered rock mass in the close laneways and the calculating of rock pillar load among laneways become one of the hot topics in the field of underground engineering.Based on study on the stress distribution of single laneway with limit equilibrium area，combining with the pressure arch theory about the activity of the covered rock mass in laneway，this paper systematically studies the stress distribution in close laneways，proposes the expansive pressure arch theory about the activity of the covered rock mass in close laneways，gives calculating formula of rock pillar loads among laneways，and points out technical measures to avoid the chain failure of the rock pillar in close laneways.

Key words: Laneways, Expansive, Pressure arch, Rock pillar load, Chain failure