| With further economic growth, the large-scale construction engineering isundergoing rapid growth. There are more and more geological problems, such asdeformation, instabilization, collapsing or sliding of slopes. The reinforcing anddeformation controlling is an emphasis in remediation works for slopes, and theyare paid attention by academia and engineer. Because reinforcing and deformationcontrolling for slopes related to a good deal of geotechnical essential problems,they associated geotechnical engineering and geological engineering extensively.Among the remediation works, prestressed anchor cables, stabilizing piles withprestressed anchor cables are practical and effective measures, which nowadayshave a wide application in many fields. However, the studies on theory of theseworks are delayed greatly than their applications. The mechanism and calculatingtheory of reinforcing and deformation controlling using prestressed anchor cablesor stabilizing piles with prestressed anchor cables are important to theory study andpractical engineering.In this thesis, according to styles of remediation works in large-scale soft orloose bed landslide, by theory study, numerical simulation and practical examplecalculation, some geotechnical essential problems are studied. Such as follows: theinteractional action between soils and anchorage section of pretressed anchorcables, and mechanism of the load-transfer along anchorage section; theinteractional action between soils and outside bearing structures, and mechanism ofthe load-transfer; the interactional action between soils and stabilizing piles withprestressed anchor cables, and their calculating theory; the distribution map formsof active earth pressure on retaining structures in soft or loose soils; soil archingeffect between adjacent piles and their spacing in loose cohesive soils.Major research works and the conclusions are summarized as follows:1. The mechanism of interactional action between soils and anchorage sectionofpretressed anchor cables, and the distribution of lateral shear stress were studied.At first, the limitation of hypothesis of thorough gluing bond between soils andanchorage section in academic analysis is analyzed. Then, based on load transfermethod and one-dimensional semi-mechanical nonlinear model inducted Mindlin'sdisplacement solution of elastic semi-infinite, the distribution of lateral shear stress was studied respectively. Furthermore, the singularity in deducing the lateral shearstress distribution based on Mindlin's displacement solution was discussed. Themanagement of singularity influenced the precision of calculating result, andprecise theoretical analysis from exact mechanical model can't be carried out yet.2. Based on the FLAC-3D numerical simulation, the interactional actionbetween soils and outside bearing structures was analyzed. It was compared usinganchor blocks and using anchor block-floor beam combined system. "Soil archingeffect" may present in situation of appropriate block spaces when pre-stress loadapplied, whereas in anchor block-floor beam system, then soil arch did not form.Furthermore, another problem of interactional action between soils and outerreaction structures, the apply procedure of steel strands was discussed, when thetension load were applied one by one to steel strands of prestressed cable inemergency remediation. Based on an elastic compressing model of the subgradeunder anchor block, a model of tension load loosening and their non-uniform wasput forward.3. Based on improved biparameters elastic subgrade reaction model in theembedding section, the active defending effect and primary internal force in pileswas derived. The universal calculation model of normal working state was putforward. Furthermore, adapted to the nonlinear character of subgrade reaction inembedding section, inducted p-y curve of subgrade reaction, calculation model wasestablished.4. There are two mechanical models and respective calculating methods of theembedding section of stabilizing piles with prestressed anchor cables, which werethe rigid pile model and the elastic pile model. By means of mathematical limitanalysis, the mechanical consistency of the two calculating methods was clarified,rigid pile model's calculating result is just only a special case of elastic pilemodel's calculating method. Only if calculating depth of pile less than 1.3 ("mmethod") or 0.8 ("K method"), the difference between two models less than 5% andit can be taken to be new dividing criterions. The mechanical effect about dips ofpile's anchoring cable and the condition of bending moment balance principle indesign were discussed.5. Distribution of earth pressure is an important problem in design anddifficult to calculating for many complex influent elements. According to measuredata of earth pressure on several representative retaining structures of soft or loose soils in Nanning-Kunming railway, theory model of a parabola distribution mapform was induced, amended and advanced. Accordingly, a simplicity map forms ofearth pressure distribution was put forward.6. By means of the analysis of "soil arching effect" between adjacent piles,taking geometrical characteristic of arch line and the fracturing face direction angleof Mohr-Coulomb failure to account, the force-balancing condition and strengthcondition are integrated. Based on Mohr-Coulomb failure criterion, the least handysoil strength parameters that only including cohesion c and internal friction angleφ,according to the relationship between the normal stress and arrow-span ratio, thearch line and spacing between piles are obtained. A concise estimate method to soilarch effect was put forward.7. Based on the practical engineering of Danba large-scale loose bed landslide,the mechanism of slide was analyzed. The effect of remediation works such asprestressed anchor cables and stabilizing piles with prestressed anchor cables wasdiscussed. A arrange method of engineering construction was put forward based onmechanism of slide and deformation characters.
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