地下洞室（underground cavity）.docVIP

地下洞室（underground cavity） Loose rock pressure is caused by rock fracture collapse and block slip and gravity collapse failure pressure, this is a limited range of falling rock mass gravity applied to the tunnel lining on the pressure Foundation bearing capacity: the capacity of a foundation to bear load on its unit area. It is divided into the ultimate bearing capacity and the allowable bearing capacity Karst: water (including surface water and ground water), the chemical dissolution of soluble rock mainly for the transformation and destruction, as well as the resulting topography and hydrogeological phenomena collectively. Karstification: mainly chemical dissolution, including mechanical fragmentation, deposition, collapse and transportation. It is a combination of chemistry and physics. Prevention and control measures of karst leakage: first, to reduce the permeability of rock mass; two, to seal the seepage channel. Measures such as filling, paving, blocking and cutting are often used. Evaluation of 3. ground sliding stability of karst foundation bearing capacity factors less than 2. main forms of karst ground collapse site deformation and failure of the 1. surface: geological structure, strata occurrence, lithology and thickness, cave shape and burial conditions, roof, filling, groundwater, seismic design intensity, building load and the importance of Karst Foundation treatment measures a replacement, repairing, impaction or cross cover, two, beam, arch structure, three span; grouting, blasting packing; four, bottom supporting or adjusting column; five, six, drilling grouting; setting the cushion; seven, adjust the area of foundation base; eight, groundwater to. Geotechnical engineering problems of karst origin may occur (1) foundation layer main pressure range, if there is a cave, underground river, the additional load or vibration under the action of karst roof collapse caused by the sudden collapse of foundation. (2) the uneven settlement of foundation is cause