Research on Seepage Characteristics of Deep Cut Canal under Dewatering Well

2013 ◽  
Vol 438-439 ◽  
pp. 588-592
Author(s):  
Kai Yun Yang ◽  
Xiang Yu Li ◽  
Lin Hao Li ◽  
Quan Long Li

In view of the problems of complex geological conditions with high underground water level, large permeability coefficient of soil and the presence of large seepage hazard of deep cut canal and deep foundation pit project of South-to-North Water Transfer Project, China, research on seepage characteristics of digging canals under dewatering well is carried out by finite element analysis, and the FORTRAN procedure is programmed. The three-dimensional finite element model of a digging canal is built, and the seepage field of the different conditions of the canal is simulated, the water head distribution, saturation line and leakages are obtained, and the rules and characteristics of steady seepage field under design impervious system are analyzed. The results indicate that the method can exactly determine the key overflow point and saturation line of canal, and well predict seepage field in canal. The results should be of guiding significance to design and construct retaining engineering in deep cut canal and deep foundation pit.

2013 ◽  
Vol 443 ◽  
pp. 79-83
Author(s):  
Zhen Xi Yu

In recent years, with the enhancement of overall national strength in China, the computer simulation technology has been developed rapidly and widely applied to engineering construction. Particularly, investment proportion of the technology in deep foundation pit engineering is immense. Yet affected by national conditions in China, the construction and application of deep foundation pit engineering have many extensive factors. It also results in insufficient vigor of finite element analysis of deep foundation pit support construction. In this way, construction problems arise frequently under the condition that there exist buildings around. With some deep foundation pit support engineering, the thesis conducts simulation analysis of the engineering through the technology of nonlinear three-dimensional finite element.Project profile


2011 ◽  
Vol 368-373 ◽  
pp. 542-548
Author(s):  
Chi Yan ◽  
Ri Song Qin ◽  
Hong Yue Sun

The fracture theory of soil was a new developing problem in recent year. In this paper, the basic principle of fracture mechanics and the strength theory of soil were combined, and the soil-cracking strength theory was adopted to build a constitutive relation for cracked soils. In order to use such theory and to analyze how the cracked soils effect on retaining structure, we developed an elastoplastic finite element program. Finally, the calculation results from this program were compared with the surveying measured in model testing.


2013 ◽  
Vol 405-408 ◽  
pp. 373-377
Author(s):  
Jing Wang ◽  
Feng Ming Sun ◽  
Jin You Chen ◽  
Chang Jie Xu

Aiming at a deep foundation pit in soil-rock composition with weak intercalated layers, in this paper, using the limit-balance method and finite element method to analyze the stability and deformation. The safety factor of foundation pit under the absence of retaining is much less than 1 through the limit-balance method, but through some retaining measures can guarantee its safety. According to the excavation of the foundation pit in special geological conditions, it takes pile-anchor retaining structure in upper and soil nailing in the lower part. Using the finite element to carry out dynamic simulation for the whole project, the results show that: this form of retaining can be very good to ensure the excavation of the foundation pit in the geological conditions, and it may be helpful for similar projects


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1303
Author(s):  
Chenghua Shi ◽  
Xiaohe Sun ◽  
Shengli Liu ◽  
Chengyong Cao ◽  
Linghui Liu ◽  
...  

At present, jet-grouted horizontal waterproof curtain reinforcement has become an essential method for deep foundation pit groundwater control. However, there is still a lack of an effective theoretical calculation method for horizontal waterproof curtain reinforcement, and there is little research on the seepage laws of foundation pits under different horizontal waterproof curtain conditions. Based on Darcy’s seepage theory, theoretical analysis models of deep foundation pit seepage were established considering the effect of a horizontal curtain in a highly permeable formation. Through the established models, the calculation method of the water inflow and the water pressure under the condition of a horizontal curtain was derived. Then through indoor tests, the reliability of the theoretical calculation method was verified. Furthermore, the established theoretical calculation method is used to analyze the influence of various factors on the water inflow and the water pressure, such as the ratio of hydraulic conductivity of the horizontal curtain to surrounding soil, thickness, and reinforcement position of the horizontal curtain. It is found that the hydraulic conductivity ratio has the most significant influence on the seepage characteristics of the foundation pit. Finally, the design method was applied to an example of the horizontal waterproof curtain of the foundation pit, which is located at Juyuanzhou Station in Fuzhou (China). The water inflow per unit area is 0.36 m3/d in the foundation pit, and this implies that the design method of the horizontal waterproof curtain applied for the excavation case is good and meets the requirements of design and safety.


2013 ◽  
Vol 838-841 ◽  
pp. 779-785
Author(s):  
Liang Gu

The double-row piles supporting structure is a new type of supporting and protecting for deep foundation excavation. It is widely used to in design of deep foundation pit. Now how to simply and effectively design the structure of double-row piles is in a research and discuss stage. Using the Midas GTS finite element method, the displacement and stress distribution of double-row piles in the different stages of excavation are obtained, and the horizontal displacement and stress distribution of double-row piles in the different stages of excavation are calculated. The results of Midas GTS finite element analysis as follows: (1) after the excavation of foundation pit, the horizontal displacement of pile-top is maximum. The horizontal displacement decreases gradually with depth increases. And the displacement of front row piles is larger than that of back row piles; (2) the maximum shear stress is at the distance 5m to the foundation basement. The higher bending moment at the pile-top and the distance 10m to the foundation basement are consistent with the actual monitoring date. (3) the results of finite element analysis is close to the Richard software and actual monitoring data. It is show that using the finite element analysis to analyze the double-row piles supporting structure with is veritable and credible.


2015 ◽  
Vol 744-746 ◽  
pp. 579-583
Author(s):  
Hui Min Wang ◽  
Zhen Jian Ji ◽  
Liang Cao ◽  
Ji Yao ◽  
Shan Guang Qian

Deep Pit is the main content of modern urban geotechnical engineering. In this paper, based on a deep foundation pit engineering as an example, based on the nonlinear finite element theory, conduct a numerical simulation research for foundation pit excavation process. Obtained the distribution law of pit deformation, stress distribution and the supporting structure of the internal forces, under the various processes. These provide a theoretical basis for safety evaluation of foundation pit engineering.


2012 ◽  
Vol 193-194 ◽  
pp. 624-632
Author(s):  
Xi Zhen Zhang ◽  
Quan Mei Gong ◽  
Shun Hua Zhou

In foundation pit engineering, the presence of pile plays an important role on the pit stability and deformation control. The bottom upheaval of deep foundation pit is a key criterion of judging the foundation stability and deformation. This paper built the 3D finite element model to analyze the influence of different factors (pile diameter, pile length and pile spacing) on the bottom upheaval, and concluded that: when pile length and pile spacing is constant, changing the pile diameter can hardly affect the bottom upheaval; as the pile length increased, the inhibitory effect to the bottom upheaval grew stronger with a gradually decreased growth rate; increasing pile spacing can significantly reduce the bottom upheaval, and the smaller the pile spacing, the smaller the upheaval. The concept of upheaval inhibition rate was defined to evaluate the influence of different factors of pile layout on the bottom upheaval. A correction method of calculating the bottom upheaval of foundation pit with engineering pile was proposed. An engineering instance of Shanghai Natural History Museum foundation pit was studied, and the result showed that the bottom upheaval calculated by the correction method is less than the upheaval calculated by method of residual stress, which was more close to the monitoring data. The influence of engineering pile on bottom upheaval of foundation pit should not be neglected where a large number of piles were present in deep foundation pit.


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