Mechanism Analysis Of Permeation Disease And Experiment Study On Impervious Material Of Longmen Grottoes

The Longmen Grottoes is one of the three world famous caves in China, which is 13km away from the south of Luoyang, Henan Province. Caves and statues of Buddha in Longmen area represent the period from the late Northern Wei Dynasty to the Tang Dynasty (the A.D. 493～907 years), the most outstanding plastic arts on the largest scale, have represented the highest peak of Chinese carving arts, which provide the important practical information for the study of Buddhism history in China and ancient carving arts The serious environmental geological diseases have been emerged in the Longmen Grottoes by natural power besides the man-made destroy for more than 1500 years.In various environmental geological influence factors, the impact on caves by permeation is particularly outstanding. The repeatability and continuation of permeation are the main external cause that destroys the caves, the limestone and dolomite stratum is the internal cause that appears the karst disease. Extensive geological disease of karst and atmospheric precipitation has caused large-scale permeation disease in Longmen Grottoes. The destruction action of permeation is divided into: physical action, chemical action, biological action The impact on caves by permeation can be summed up roughly: cause empty structure of the walls , destroy the integrity of the caves and the carving , a large amount of calcium carbonate deposit pile up on the carvings' surface that make the caves lose the artistic value.Through the formation mechanism analysis of the permeation disease of Longmen Grottoes, can know that prevention of permeation is the basic route to control the Longmen Grottoes disease. Combine with the special environmental condition, rock characteristics and rock structure in the district of caves , prevention of permeation should process firstly with fissure grouting , adopt a control program combined with stop up and drain . In field test, we adopt superfine cement, water-borne epoxy resin and nanophase material to examine the grouting effect. In laboratory, the test of modified research of the water-borne epoxy resin has been done. Combine with various materials performance parameters enduced from the field tests and the laboratory tests, compare the micro structural characteristics .mechanics performance and resistance of weathering , at last choose a predominant material suitable for fissure grouting. Confirm the construction craft and method through the field tests.The following conclusions can be drawn through this research:1 Through the observation of field tests, may know that the superfine cement is easy to construct and has good grouting effect. But the superfine cement has the problem that it exudes salt and alkali, can only be used in the grouting of the rock fissure outside the caves.2 The mechanics performance of the water-borne epoxy resin is superior than the cement, and can resist the acid and alkali . But it solidifies slowly, generates moisture when solidify, shrinks heavy and is apt to crack, still there are certain requirements to the construction equipments when grouting with the water-borne epoxy resin.