The Design Optimization And Experimental Study On The Mold Bag Concrete Revetment At Lock Approach

The mold bag concrete revetment has the features of good integrity, durability, high terrain adaptability, speed of construction and filling can be laid underwater and other characteristics. It is widely used of river slope protection,rescue and repair engineering. This paper research on the design optimization and experimental study by the mold bag concrete revetment take as an example in Changgou lock approach. The main contents and conclusions of this paper are as follows:(1) According to investigate mode of damage of the mold bag concrete revetment, this paper analysis of the mold bag concrete revetment damage mechanism. The study shows that the damage of the mold bag concrete revetment in two ways that collapse-type damage and slip-type overall damage.The reasons of the collapse-type damage have two types. The first types is that the concrete of revetment cracks and local rise causes that revetment is emptied below the the mold bag. The second types is that the factors of river erosion or seepage causes that revetment toe is emptied. Then the revetment develops into emptying. The reasons of the the slip-type overall damage also have two ways that rainfall and river water level and the water table elevation greater(2)The finite element is used of slope stability analysis method to build calculation model by the mold bag concrete revetment take as an example in Changgou lock approach through the study of the failure mechanism of the mold bag concrete revetment.Then the stability of the natural slope and the mold bag concrete revetment calculate through the model. The results show that when the safety factor of 3.4, the plastic zone run through the revetment and the mold bag concrete revetment damaged.(3)The mold bag concrete revetment in lock approach would be designed optimization of based on the stability of the revetment. First of all, the design parameters of bag thickness is selected, and formula for calculating the thickness of the mold bag concrete revetment considering the case of ship waves according to the elastic surface sheet differential equations. The results show that reducing the thickness of to the mold bag concrete revetment 150mm is possible through considering the economic and security basing on the concrete whether cracks by the ship hit revetment. Then according to the count, the results show that concrete slab of the mold bag concrete revetment does not meet the requirements of deflection in concrete specification in probe point SMI. These results indicate that the soil compaction degree should be introduced of design parameters. According to the calculation of the five kinds soil compaction degree of the subsidence on top soil, the results show that when the degree of soil compaction reach 92%, the designe is optimization that the result can achieve requirements, and consistent with the principle of economy.(4) According to summarize the data and influence factor of filling, the experimental study has selected two different factors of soil moisture, aquatic and underwater construction basing on unchanging concrete water-cement ratio. By testing the workability (slump) of concrete, it can fill the bag completely, improve the efficiency of construction and account the economic.For the mold bag concrete revetment in Changgou lock approach,the result of the first group of test soil moisture show that it recommends that soil moisture is 24-26% and slump is 225-235mm. The results of the two group of test above-water and below-water construction show that when the mold bag concrete revetment exist both above-water and below-water construction forms, it recommends that the engineering uses the same slump and slump is 235-245mm. When the mold bag concrete revetment has only a single form of under-water revetment, it recommends that slump is 230-235mm.The conclusions of the design parameters optimization with the mold bag concrete revetment in this paper seek to provide a strong technical support for design. The conclusions of the experimental study have good promotional value and reference in the construction of the mold bag concrete revetment.