The invention relates to a cement-base composite material for grouting treatment of water-rich fractured rocks and a preparation process of the cement-base composite material. The cement-base composite material for grouting treatment of water-rich fractured rocks comprises, by mass, 69-77 parts of portland cement clinker, 23-31 parts of mineralizer and 0.34-1.55 parts of additive powder retarder. The mineralizer comprises, by mass, 75-79 parts of ground quartz, 6.8-7.6 parts of calcium chloride, 2.8-3.6 parts of lithium chloride, 1.9-2.4 parts of talcum powder, 2.0-2.5 parts of hydroxypropyl methyl cellulose, 2.1-2.6 parts of wollastonite powder, 0.6-0.9 part of titanium dioxide, 3.1-3.8 parts of sodium hexametaphosphate and 1.5-2.1 parts of super plasticizer. Since portland cement clinker and mineralizer are processed by the combined grinding technology, and specific surface area of the material is controlled to be larger than 500m2/kg and residue on sieves of 80 micrometers in a vacuum sieving process is controlled to be less than 8% respectively by the Blaine method and the vacuum sieving analysis method, uniform performance of the material is achieved. Condensation time of the material is controllable, the strength of the material is high in early stage and later period, volume expansion of the material is slight, retention of the material is over 91% on a condition of 30m/min flowing water, and accordingly, the material can be applied to grouting reinforcement treatment engineering of water-rich fractured rocks widely.

Focused on the failure modes of prestressed anchor cables, according to Hoek-Brown failure criterion and associated flow rule, the ultimate pullout force and failure mechanism of anchor cable were deduced through upper bound limit analysis, where bond failure of anchorage body and anchored rock mass failure were considered respectively. The influences of grouting pressures, lengths of anchorage section and rock parameters on ultimate pullout forces and failure mechanisms were analyzed. The results reveal that, increasing anchorage length in a certain extent and using pressure grouting are effective measures to improve ultimate pullout forces of anchor cables. When anchored rock mass failure occurs, ultimate pullout forces will increase with the improving of empirical parameter A, tensile strength, compressive strength and unit weight of rock mass, while it will decrease with the improving of empirical parameter B. The shape of failure surface of anchored rock mass looks like horn, which is consistent with the conclusions of existing literatures;and parameter B is a key factor affecting the shape of failure surface of rock mass;it determines the curvature of failure curved surface;and curved surface will degenerate into circular conical surface when B is equal to 1.

In order to clarify the basic mechanical properties of the latest invented U-type confined concrete arch centering, the axial compression experiment program of U-type confined concrete (UCC) short columns is designed. And from the aspect of deformation and failure modes, load-strain curves, ultimate bearing capacity, core concrete response characteristics of the acoustic emission and so on, the mechanical behavior, deformation and failure character are analyzed, and the fracture mechanism of core concrete is researched. The study result shows that the failure modes of UCC short columns under the axial compression is in overall plastic instability, and the N-εcurve shows the rise→gent ly rise 4 stage type. UCC short columns have better ductility and post-bearing capacity, with the ultimate beating capacity increasing by 127%~196%. Accordingly, the economy improves. Acoustic emission activity shows 4 periods:incubation→active→stabilization→elimination death. At the same time the defo r-mation&failure behavior and mechanism of UCC short column are obtained by comprehensive analy-sis. The application effect shows that UCC arch centering is a new effective support for deep and soft rock roadway, and the surrounding rock controlling effect is much better than U-steel arch centering.

According to roof collapse characteristics of large section roadway with thick top coal, a failure mechanism of roof collapse block, considering the influences of the stress of surrounding rock and supporting pressure, was constructed based on Hoek-Brown failure criterion and its associated flow law. Through upper bound limit analysis, the roof collapse mechanism of large section roadway with thick top coal was deduced with variational principle; and with one roadway in Zhaolou coal mine, for example, the influences of rock parameters on roof collapse mechanism were also analyzed. The calculation results show that: With the increasing of empirical parameter A, tensile strength, compressive strength and supporting pressure, the size of collapse block increases, while decreases with the increasing of empirical parameter B, the stress of surrounding rock and unit weight of rock mass. The size of collapse block represents the roof stability, larger size means more external work to expend, and the roof is more stable. The parameter B, the stress of surrounding rock and supporting pressure have significant impacts on roof collapse mechanism; and the parameter B determines the shape of failure curved surface; the curvature of failure surface will decrease with the increase of parameter B. Improving supporting pressure is an effective way to increase the roof stability, which provides theoretical basis for the support design of large section roadway with thick top coal.

Considering the problem of conventional anchor belt net and cable support in deep roadway, taking typical deep thick top coal roadway of 11301 working face crossheading in Zhaolou coal mine in shangdong province, as engineering background, two longitudinal-lateral combined steel band support programs were designed, which have single longitudinal steel band and double longitudinal steel bands, respectively. The results of numerical test and field test show that the two programs are both good for surrounding rock controlling, and the longitudinal single steel band program is better in surrounding rock controlling; the effect of surrounding rock controlling has a positive correlation with confining pressure values and range of roof caused by support resistance. The test results of roof settling, roof bending, support unit stress and roof stress were analyzed, and the mechanism of longitudinal-lateral combined steel band support was summarized. The results show that: (1) central roof of deep thick top coal roadway is the key position for surrounding rock controlling, longitudinal steel band in central roof is good for controlling roof bending deformation and the rigid stability of roof; (2) longitudinal steel band is good for surface protection area expansion and improving distribution of support resistance; (3) longitudinal steel bands reduce the loss of anchor prestressing force effectively, and ensure that the support system has high initial anchor-hold and the late support resistance; (4) 3-D controlling system is made up of longitudinal steel band and lateral steel band, enhancing the overall rigidity and support ability of support system. Longitudinal-lateral combined steel band support mode is good for expansion of application range of anchor belt net and cable support and improves surrounding rock controlling effect, and support program has advantage of easy application and low support cost.

The current situation of coal roadway support,especially pressure relief support theory and technology,was summarized.The necessity and engineering significance of the support idea,which is controlling at first,pressure yielding behind and then resistance,was researched.Guided by the support idea,and considering the demand of deep high stress coal roadway support,high strength pressure relief anchor box beam support system was developed,and the high strength pressure relief performance of the system was analyzed,and the function and mechanical property of box supporting beam,yielding link and other combined members were researched.The contrastive analysis with channel steel and I-beam indicated that box supporting beam had the advantage of high strength and stiffness,high-level economical efficiency,good surface protection effect and load-transmitting performance.The result of uniaxial compression test showed that the yielding link had unique second order determinant pressure relief performance,high pressure relief point,long pressure relief distance and good pressure relief stability.The supporting system has the advantage of multiple compound mode,wide area of application and easy application.Based on geological condition of 3302 headentry in Zhaolou coal mine,high strength pressure relief anchor box beam support scheme was designed and simulated.Result shows that the new scheme is better than the original,achieving good support effect in the test section of headentry.