中文摘要：

研究圆巷＂开挖-支护＂过程中掘进头附近承载结构形成机理和发展规律。基于Drucker-Prager屈服准则和Levy-Mises本构关系,考虑开挖损伤因素,获得围岩次生应力场、位移场的解析式,由蠕变效应推导承载结构演化方程组。依据切向应力＂增-减-集中-趋稳＂划分次生承载结构为＂主动-被动-关键-自稳＂承载圈,由算例可知,随着岩性增强和支护力增大以及掘巷速度、损伤程度、锚杆间排距和地压的减小,＂主动-关键＂圈更靠近巷壁,其中＂关键＂圈厚度和应力集中系数增大,使得围岩初始支护难度减小、承载能力增强。各承载圈厚度及与巷壁间距离随着蠕变效应发生变化,当地压在20 MPa时,采用锚杆支护力为0.4 MPa、间排距600 mm×600 mm,及时地封孔注浆减小软化系数,有助于提高围岩承载能力,加快进入蠕变稳定期,并有效地控制住＂关键＂圈转移,抑制其厚度增大,降低巷道后期维护难度。

英文摘要：

The formation mechanism and development law of secondary bearing structure near the ex- cavation face during the process of ＂excavating-supporting＂ in circular roadway was analyzed. Based on Drucker-Prager yield criterion and Levy-Mises constitutive relation, considering excavation damage factor, the analytic formula of secondary stress-displacement field was obtained, and the equations of secondary carrier structure evolution was derived through creep effect. According to tangential stress ＂increase-decreases-concentration-stabilizing＂ secondary bearing structure was divided into ＂ac- tive-passive-key-stability＂ bearing ring, and the example results have revealed that with the increase of rock mass strength and supporting force, and the decrease of driving speed, ground-pressure, bolt inter-val as well as the damage degree, the ＂active-key＂ bearing ring is more closed to the roadway wall, ＂critical＂ circle thickness and stress concentration increases, which decreases the surrounding rock first supporting difficulty, and reinforces the bearing capacity. With creep effect, the scope of bearing ring and the distance with wall change. When the ground-pressure is 20 MPa, grouting in time to reduce the softening coefficient with the supporting force of 0.4 MPa and bolt interval of 600 mm X 600 mm is helpful to improve the bearing capacity of surrounding rock, to accelerate into the creep stability, and to control the ＂key＂ bearing ring transfer and restrain the increase of thickness, and reduce the difficulty in following-up maintenance of roadway.