Parameters determination and bolting control of gateway floor

Gateway floor heave control is the key to guarantee mine safe and efficient production. Through analysis of floor instability characteristics and bolting control, gateway floor strata show second level stress under abutment pressure, which causes plastic flow failure in floor strata; gateway floor instability shows mainly shear-break slippage of ＂triangle sliding body＂. Mechanics of floor bolting is mainly a function of connection and combination. Main area of bolting control lies in two gateway floor angles. The paper analyzes mechanics principle of gateway floor instability, constructs stability mechanics model of gateway floor bolting, obtains gateway floor stability criterion of different bolting angles and optimum formula of bolting parameters, carries out the engineering example, and guides better field application. It provides theoretical base for bolting gateway floor instability control.