The Study On Construction Design And Used In Deep Excavation On Composite Supporting System

Excavation engineering mainly include excavation support system design and construction, and soil excavation etc. It is strong comprehensive system engineering. Because geological conditions of every area are different, excavation engineering has a very strong regional and individual characters. The soil pressure that support systems bear has stronger space-time effect too. It is excavation engineering regional and individual characters that offer us bigger space to research the design knowledge of excavation support, study corresponding excavation stability, and internal force and displacement of the support structure, the impact on the building around and underground pipeline of displacement of the stratum, and computational analysis of protection. By that means, we can adopt the economic and practical excavation support project. So it has the important theoretical and reality meanings.This text has carried on research to above-mentioned problems, the main content includes: (1) the choice of excavation support method. Combine the commonly used support structure form at present, the author put forward the characteristic composite using many support structure forms; (2) the study on water seal ,precipitation and drainage measures. Put forward the influence on support engineering stability by precipitation system. (3)Combine project reality, this paper put forward new design project of the support structure. Include choice of scheme, support system design of soil-nailing wall and anchor-pile composite supporting structure, excavate and monitor measurement in excavation engineering. It discusses especially the finite element method on anchor- pile support in deep excavation and on design computing of soil-nail wall. (4) This paper demonstrates the issue with the case study and real design data, and achieves the design purpose through practice.Excavation support systems generally include soil retaining system and drainagesystem; it generally bears soil pressure and water pressure. So its choices are greatly affected by area, and the levels of underground water have greatly influent on support system choice, for example. The composite application of many support methods is the effective way to research the problems of excavation supporting structure engineering in some special regions.The researched excavation has two completely different structures. The top of it adopt soil-nail wall and the bottom adopt slope protection pile combined with two bolting. There drill precipitation wells around the excavation. This text calculates the single anchor stock and many anchor stocks respectively.The calculation of single anchor support structure adopts static balance method and equivalence beam method respectively. According to trial method, depth of penetration t needs to be supposed in advance, and then calculate support strength. On the safe side, we should use active soil pressure and passive soil pressure to calculate the support strength before T increased. That is RA =EA -EP .Immediately, flexural torque distribution of enclosure wall can be counted. Mmax is the location of shear force zero. Equivalence beam method abridges.No matter which kind of supporting structure form, the key problem lies in the establishment depth of catch point, severity of support and enclosure wall, penetration depth and pit bottom quality of soil property. By the contrast the calculate result of single anchor supporting structure between the elastic ground beam method and commonly used equivalence beam method, we can draw the following conclusions:(l)The depth of catch point exerts a great influence on security of the structure. When the point position shift down, the greatest horizontal displacement will shift up, at the same time the flexural torque peak value of the pile body is obviously reduced. Namely catch point shift down to certain depth is benefit to enclosure wall strength state, but it is useless to control the displacement of top wall. (2) Penetration depth of enclosure wall. When the depth increases, the displacement of...