The Monitoring and Analysis of the Anti-Slide Pile’s Pile-Soil Interaction

2014 ◽  
Vol 633-634 ◽  
pp. 952-957
Author(s):  
Nian Qin Wang ◽  
Yao Qiong Xue ◽  
Xiao Yu Cheng ◽  
Jing Rui Wei

In the landslide disaster control and high slope strengthening engineering, anti-slide pile is one of trusted engineering measures, but cognition in aspect of forced state on the anti-slide pile, the pile-soil mechanism etc, which should be strengthened. Therefore, monitoring objects with three cantilever anti-slide pile entities in the loess high slope somewhere, burying monitoring instruments such as earth pressure cells and steel bar meter, for as long as 18 months of monitoring. Through analysis of monitoring results, can draw the following conclusion:①The soil pressure distribution form before the anti-slide piles is parabola-shape as a whole, whatever above the slip surface or under the slip surface the soil pressure distribution form behind the anti-slide piles is almost triangle as a whole;②The anti-slide piles construction are completed, pile-soil interaction force and reinforced by stress reaches stability in about 16 months;③A maximum soil pressure before the anti-slide piles on the ground, the soil pressure behind the anti-slide piles near the potential sliding surface;④Before the anti-slide piles and behind the anti-slide piles, reinforced by stress from pile cap to pile bottom respectively is "compressive stress and tensile stress" and "compressive stress, tensile stress and compressive stress, tensile and compressive stress of zero before pile is tensile stress value maximize after pile.

2013 ◽  
Vol 353-356 ◽  
pp. 312-317
Author(s):  
Ying Yong Li ◽  
Li Zhi Zheng ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Zhi Chao Xue

In order to ensure the security of gravity retaining wall in the high fill subgrade, the design of gravity retaining wall with anchors is proposed,the characteristic of the new wall is that comment anchors are added to the traditional gravity retaining wall,by friction anchors provide lateral pull to the wall so the stability of the new wall is improved. Because of the constraints of anchors, the lateral free deformation is influenced and the soil pressure distribution is very complicated, field tests showed that soil pressure distribution is nonlinear and pressure concentrate in anchoring position. In order to reveal the supporting mechanism of retaining wall and propose the soil pressure formula, the model test of anchor retaining wall is made and numerical simulation is done. The results show that soil pressure appears incresent above the anchor and decreasing below the anchor, the soil pressre also grew larger away from the anchor proximal in the horizontal direction.


2013 ◽  
Vol 671-674 ◽  
pp. 1217-1220
Author(s):  
Yong Wei Wang ◽  
Hong Xia Li ◽  
Yan Qin Guo

Combining with a mountain highway retaining wall earth pressure measured data, carried out a detailed study of the of multiple retaining wall back soil pressure distribution law, based on multi-level retaining wall measured horizontal earth pressure data mountainous retaining wallshorizontal earth pressure formula is derived, summed up the horizontal earth pressure with filling height variation.


2012 ◽  
Vol 204-208 ◽  
pp. 1929-1932
Author(s):  
Peng Li ◽  
Hai Tao Wan

This study presents the research of soil pressure distribution form of multi-stage mountain gravity retaining wall through specific engineering tests. There has a further discussion on the soil pressure calculation formula of the multi-stage gravity retaining wall in different conditions, which aims at providing the useful reference for the formal construction design.


1996 ◽  
Vol 23 (2) ◽  
pp. 315-322
Author(s):  
Lorne C. Boone ◽  
David C. Sego ◽  
S. Peter Dozzi

The feasibility of building residential basement foundation walls of unreinforced concrete thinner than the conventional 200 mm thick wall is investigated. An optimum thickness of 150 mm was determined for an unreinforced 2400 mm high foundation wall based on the use of equivalent fluid pressures with sand and gravel backfill material. For walls backfilled with other than clean sand and gravel, or with a submerged condition, it was found that the theoretical maximum backfill heights for both 150 and 200 mm walls are substantially less than those presently specified by the Alberta Building Code. The primary purpose of the study described in this paper was to test under actual field conditions the performance of a 150 mm unreinforced concrete wall under varying lateral loads imposed by different soil types, and to compare measured and calculated lateral loads with the equivalent fluid pressure specified as a criterion in the Alberta Building Code. The lateral earth pressures resulting from the backfilling of 150 mm thick concrete foundation walls were investigated for two backfills, namely sandy lean clay (clay till) and sand. The findings indicate that for longer term placement conditions, the resulting pressure distribution supports the hypothesis of a triangular soil pressure distribution and can be described using traditional earth pressure theory. Two design methods based on the concept of equivalent fluid density were evaluated and compared with the field measurements. Key words: thin wall foundations, earth pressure, field measurement.


2020 ◽  
Vol 29 ◽  
pp. 2633366X2095872
Author(s):  
Yang Wei ◽  
Mengqian Zhou ◽  
Kunpeng Zhao ◽  
Kang Zhao ◽  
Guofen Li

Glulam bamboo has been preliminarily explored for use as a structural building material, and its stress–strain model under axial loading has a fundamental role in the analysis of bamboo components. To study the tension and compression behaviour of glulam bamboo, the bamboo scrimber and laminated bamboo as two kinds of typical glulam bamboo materials were tested under axial loading. Their mechanical behaviour and failure modes were investigated. The results showed that the bamboo scrimber and laminated bamboo have similar failure modes. For tensile failure, bamboo fibres were ruptured with sawtooth failure surfaces shown as brittle failure; for compression failure, the two modes of compression are buckling and compression shear failure. The stress–strain relationship curves of the bamboo scrimber and laminated bamboo are also similar. The tensile stress–strain curves showed a linear relationship, and the compressive stress–strain curves can be divided into three stages: elastic, elastoplastic and post-yield. Based on the test results, the stress–strain model was proposed for glulam bamboo, in which a linear equation was used to describe the tensile stress–strain relationship and the Richard–Abbott model was employed to model the compressive stress–strain relationship. A comparison with the experimental results shows that the predicted results are in good agreement with the experimental curves.


2018 ◽  
Vol 8 (12) ◽  
pp. 2598 ◽  
Author(s):  
Haiying Ma ◽  
Xuefei Shi ◽  
Yin Zhang

Twin-I girder bridge systems composite with precast concrete deck have advantages including construction simplification and improved concrete strength compared with traditional multi-I girder bridge systems with cast-in-place concrete deck. But the cracking is still a big issue at interior support for continuous span bridges using twin-I girders. To reduce cracks occurrence in the hogging regions subject to negative moments and to guarantee the durability of bridges, the most essential way is to reduce the tensile stress of concrete deck within the hogging regions. In this paper, the prestressed tendons are arranged to prestress the precast concrete deck before it is connected with the steel girders. In this way, the initial compressive stress induced by the prestressed tendons in the concrete deck within the hogging region is much higher than that in regular concrete deck without prestressed tendons. A finite element analysis is developed to study the long-term behaviour of prestressed concrete deck for a twin-I girder bridge. The results show that the prestressed tendons induce large compressive stresses in the concrete deck but the compressive stresses are reduced due to concrete creep. The final compressive stresses in the concrete deck are about half of the initial compressive stresses. Additionally, parametric study is conducted to find the effect to the long-term behaviour of concrete deck including girder depth, deck size, prestressing stress and additional imposed load. The results show that the prestressing compressive stress in precast concrete deck is transferred to steel girders due to concrete creep. The prestressed forces transfer between the concrete deck and steel girder cause the loss of compressive stresses in precast concrete deck. The prestressed tendons can introduce some compressive stress in the concrete deck to overcome the tensile stress induced by the live load but the force transfer due to concrete creep needs be considered. The concrete creep makes the compressive stress loss and the force redistribution in the hogging regions, which should be considered in the design the twin-I girder bridge composite with prestressed precast concrete deck.


2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Kaiyang Wang ◽  
Yanjun Shang

This paper examines the performance of a novel technology, vertical steel floral tube micropiles with double grouting. It is the combination of micropile technology and double grouting technology. A large-scale model tank was applied to impart horizontal bearing capacity, and the slope soil pressure and flexural performance of the micropile were investigated under four experimental conditions. The peak grouting pressure during the double grouting process was defined as the fracturing pressure of the double grouting, and it was positively correlated to the interval time between first grouting and secondary grouting. Compared with traditional grouting, double grouting increased the horizontal bearing capacity of the single micropile with the vertical steel floral tube by 24.42%. The horizontal bearing capacity was also 20.25% higher for the structure with three micropiles, compared with a 3-fold value of horizontal sliding resistance. In the test, the maximum bending moment acting on the pile above the sliding surface was located 2.0–2.5 m away from the pile top, and the largest negative bending moment acting on the pile below the slip surface was located 4.0 m away from the pile top. The ultimate bending moment of the single pile increased by 12.8 kN·m with double grouting, and the bending resistance increased by 96.2%. The experimental results showed that the double grouting technology significantly improved the horizontal bearing capacity of the micropile with the steel floral tube, and the soil reinforcement performance between piles was more pronounced. Also, the shear capacity and the flexural capacity were significantly improved compared with the original technology.


Author(s):  
Bethanie A. Parker ◽  
Rodney P. McAffee ◽  
Arun J. Valsangkar

An induced trench installation was instrumented to monitor earth pressures and settlements during construction. Some of the unique features of this case study are as follows: (a) both contact and earth pressure cells were used; (b) part of the culvert is under a new embankment and part was installed in a wide trench within an existing embankment; (c) a large stockpile was temporarily placed over the induced trench; and (d) the compressible material was placed in two stages. The maximum vertical pressure measured in the field at the crown of the culvert was 0.24 times the overburden pressure. The maximum horizontal pressure measured on the side of the culvert at the springline was 0.45 times the overburden pressure. The column of soil directly above the compressible zone settled approximately 40% more than did the adjacent fill. The field results at the crown and springline compared reasonably with those observed with numerical modeling. However, the overall pressure distribution on the pipe was expected to be nonuniform, the average vertical pressure calculated by using numerical analysis on top of the culvert over its full width was 0.61 times the overburden pressure, and the average horizontal pressure calculated on the side of the culvert over its full height was 0.44 times the overburden pressure. When the full pressure distribution on the pipe is considered, the recommended design loads from the Marston–Spangler theory slightly underpredict the maximum loads, and the vertical loads control the design.


2019 ◽  
Vol 944 ◽  
pp. 1088-1093
Author(s):  
Jun Chen ◽  
She Wei Xin ◽  
Wei Zhou ◽  
Qian Li ◽  
Si Yuan Zhang ◽  
...  

TA24 titanium alloy pipe with 638mm diameter and 19mm wall thickness is carried out continuous load flatten test, and the stress of internal and external pipe wall during flatten process is studied in this paper. The results show that the TA24 titanium alloy tube has good flattening performance, and the flattening process has experienced original stage, flattened oblate stage, flattened straight wall stage, flattened depressed stage, flattened concave contact stage. During the flattening process, the outer layer of the upper and lower wall of the tube is subjected to compressive stress, and the inner layer material is subjected to tensile stress. The tensile and compressive forces cause the vertical part of the upper and lower walls to be concave. The outer layer of the left and right circular arc parts is subjected to tensile stress and the inner layer is subjected to tensile stress. The compressive stress also causes the radius of the arc to decrease due to the combined force of the tensile and compressive forces, that is, the flattening occurs. With the decrease of and pressing distance under continuous loading condition, the metal on the left and right sides of the pipe gathers toward the middle depression, which aggravates the deformation of the upper and lower walls until the upper and lower walls contact, and the arc radius of the left and right walls decreases until the outer surface cracks. The pipe microstructure changes significantly into elongated deformation structure during the flattening process. The most severe part of the deformation is the left and right end arc of the pipe, followed by the upper and lower end depression.


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