Research On Prestressed (Distribution) Tendon's Mechanism Study And Using In Engineering

Prestressed tendon has been widely used in geotechnical engineering. It can exert the surrounding rock's elastic modulus, enhance the rock's stability, reduce the supporting structure loads, save the engineer invest, and ensure the safety and stability, and it can bring many economic and social benefits. But the theory research of prestressed tendon is behind the engineering practice, and the methods of analysis is immature and many engineering problems has not been solved. Blcause of the complex mechanism and many existing impacting factors, the reforceing mechanism's research and its guidance to the tendon's construction are important to improve our contury's prestressed tendon theory and the engineering application. This paper studies the prestressed tendon reinforcement mechanism and design optimization, based on the crag segments(K119+500～K120+130)of the national main road-GZ40(Yibing～Shuifu). Firstly it use the Heok-Brown strength criterion to analyses the rock mass mechanics parameter, on the basis of the local rock mass investigation and in-house experiment results; it establishes the computational model of the crag segments according to the analysis of the forming mechanism of the crag segments; and it opens out the effects of the relationship between the slope structure-prestressed tendon-rock slope, which provide the placement of the prestressed tendon in the crag segments with the scientific basis. As another important subject in this paper, the pressure and distribution pressure tendon's floor distance and stress's distribution rule, the distribution rule of the tendon grout's stress and strain, and the distribution rule of the shearing strength on the contact area between the grout and surrounding rock, have been studied with 3D FEM.model, and made clear the transimission regularity of anchoring force. Base the analsis, the axes distance, axes stress and the shearing strength count formula have been established, and take account of the deform assume, the calculate formula of anchorage length has been founded. The formulation afluent reflects the anchoring force,surrounding rock's elastic modulus, and the contact resistance intensity parameter(C,φ). The examples indicate that the formula is closer to the practical condition than the normative method, and more reasonable theoretically With the changing of the surrounding rock's elastic modulus, the transimission regularity of anchoring force also has been studied in this paper, as well as the interaction and impact between the two loading plates of pressure distribution tendon.