About Errors Engineering and Deviceing Anchor Piles, Performed by Discharge-Pulse Technology

2020 ◽  
pp. 13-21
Author(s):  
D.G. Samarin ◽  
◽  
A.A. Filippovich ◽  
V.L. Ustyuzhanin ◽  
◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Foundation Pit ◽  
Discharge Pulse ◽  
Parking Lot ◽  
Under Construction ◽  
Preliminary Tension ◽  
Pulse Technology

The article examines a case from the practice of geotechnical construction, when errors in the calculations of anchor piles performed by discharge-pulse technology (DPT anchor) and deviations from engineering solutions could lead to an emergency. During excavation of the foundation pit, an underground parking lot under construction, the enclosing structure, fixed with DPT anchors, received unacceptable displacements. Calculations established that the bearing capacity of the DPT anchors on the ground was overestimated up to 3 times. In addition, the analysis of the available materials on this object allowed the authors to identify serious violations in the construction of the latter. It is shows that when carrying out work on the preliminary tension of the DPT anchors, in some cases, already with an effort of 10 tons, there is a loss of their bearing capacity along the ground. As a result, it became necessary to redesign the anchorage.

Discharge-pulse Geotechnical Electro Discharge Technology of Bases Strengthening

2020 ◽  
Vol 787 (12) ◽  
pp. 63-65
Author(s):  
N.S. Sokolov
Keyword(s):  
Bearing Capacity ◽  
Mechanical Characteristics ◽  
Discharge Pulse ◽  
Zero Values ◽  
Traditional Technologies ◽  
Negative Friction ◽  
Geotechnical Problems ◽  
Physical And Mechanical Characteristics

The problem of increasing the bearing capacity of the base is an relevant problem in modern geotechnical construction. When significant loads are transmitted to the base, the use of traditional technologies is not always justified. Often there is an urgent need to use non-standard ways to strengthen the bases. In many cases, the geotechnical situation is aggravated by the presence of weak underlying layers with unstable physical and mechanical characteristics in engineering-geological sections. When strengthening such bases with the help of traditional piles, the latter can get negative friction, which significantly reduces their bearing capacity on the ground, sometimes reaching zero values. This may lead to additional precipitations of the objects being constructed and constructed in the zone of geotechnical influence. The use of ERT piles in most cases successfully solves many complex geotechnical problems.

scholarly journals Study on Flexural Bearing Capacity Calculation Method of Enclosure Pile with Partial Excision in Deep Foundation Pit

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Mingfeng Lei ◽  
Linghui Liu ◽  
Yuexiang Lin ◽  
Jin Li
Keyword(s):  
Flexural Strength ◽  
Bearing Capacity ◽  
Calculation Method ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Theoretical Derivation ◽  
Deep Foundation Pit ◽  
Practical Engineering ◽  
Capacity Calculation ◽  
Partial Excision

During deep foundation pit construction, the structural clearance intrusion, which is caused by the complex formation conditions and the inefficient drilling equipment, is usually detected due to the vertical deviation of piles. To meet construction requirements, pile parts intruding into the structural clearance are supposed to be excised. However, the sectional flexural strength of the pile is bound to decrease with partial excision, which would reduce the bearing capacity of the enclosing structure during construction. In this paper, a theoretical derivation of the normal sectional flexural strength of the partially excised circular pile is proposed. The derivation adopts the assumption of the plane section and steel ring equivalence and can be solved by the bisection method. Furthermore, the calculation method is applied to the pile evaluation of a practical engineering; also, the method is verified by the numerical method. The application results show that the excision of rebar and pile’s sectional area will cause a rapid linear decline in the sectional flexural strength. After excising 18 cm radial thickness of the circular pile (ϕ800 mm) and 6 longitudinal rebars, the sectional flexural strength of the pile decreases to 58% from the origin, which cannot meet the support requirement. The analysis indicates that pile reinforcements must be carried out to maintain the construction safety.

The Increasing Laws of the Foundation Strength and Civil Engineering

2011 ◽  
Vol 250-253 ◽  
pp. 2662-2666
Author(s):  
Zhi Hai Qin ◽  
Tong Dong Li
Keyword(s):  
Water Stress ◽  
Bearing Capacity ◽  
Pore Water ◽  
Effective Stress ◽  
Civil Engineering ◽  
Building Construction ◽  
Foundation Pit ◽  
Engineering Construction ◽  
Building Load ◽  
Over Time

In the civil engineering construction, with the building load of building construction or adding storeys, foundation pit dewatering, embankment filling , over time, the pore water stress that is borne by pore water in the foundation decreases gradually, the effective stress that is borne by particle increases gradually, the foundation bearing capacity increases gradually, we use different methods to derive the variation law in the theoretical solution, and carry on the comparison, then get the same conclusion. By using theory to solve the frequently encountered problems during civil engineering construction, including the problems of building construction or adding storeys, foundation pit dewatering, embankment filling, it provides theory basis for both economical and safe civil engineering construction .

Research of a New Form Traveler on Cable-Stayed Bridge

2013 ◽  
Vol 333-335 ◽  
pp. 2119-2122
Author(s):  
Xiao Lei ◽  
Yong Jun Zhou ◽  
Yu Feng Liu ◽  
Yu Zhou ◽  
Jian Min Wang
Keyword(s):  
Southeast Asia ◽  
Bearing Capacity ◽  
Main Beam ◽  
Loading Test ◽  
Construction Stage ◽  
Cable Stayed Bridge ◽  
New Form ◽  
Under Construction

The second Penang Bridge is a new bridge under construction in Penang, and will become the longest bridge in Malaysia and Southeast Asia. The purpose of this test is to estimate the bearing capacity of the form travelers in the second Penang Bridge. The pre-loading test simulates the construction stage of the typical edge beam and slab section. By observing the strain and deformation data of the form travelers, stress and displacement were analyzed to ascertain the performance and safety of form travelers and to provide evidence for the main beam alignment control in construction.

A Discussion of the Stability of Foundation Pit or Slope with Soft Interlayer or with Back Berm

2014 ◽  
Vol 1065-1069 ◽  
pp. 96-99
Author(s):  
Hai Ying Hu ◽  
Xiao Wen Zhou ◽  
Zhi Xing Huang
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
High Water ◽  
High Water Content ◽  
Sliding Surface ◽  
Foundation Pit ◽  
Soft Interlayer ◽  
The Difference ◽  
The Stability ◽  
Slice Method

The soft soil in Pearl River Delta regions is characterized with high water content, high compressibility and low bearing capacity. Therefore, when building the structures on such foundation, it’s necessary to pay attention to the deformation and stability. The projects' practice shows that, when analyzing the stability on foundation pit or slope with soft interlayer, it should not only calculate the overall stability of the slope, but also calculate the stability or bearing capacity of the foundation. Although sometimes the stability of the slope meets the requirements, it doesn’t means that the bearing capacity of the foundation meets the requirements because of the existence soft interlayer, the limitations of the circle slice method and the difference between the sliding surface and the actual sliding surface.

scholarly journals An approach to increasing the load-bearing capacity of drilled injection piles

2021 ◽  
Vol 274 ◽  
pp. 03016
Author(s):  
Nikolay Sokolov
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Residential Building ◽  
Longitudinal Axis ◽  
Reinforced Concrete Structure ◽  
Load Bearing Capacity ◽  
Buried Structures ◽  
Load Bearing ◽  
Under Construction ◽  
Foundation Plate

The problem of strengthening weak or overloaded bases is an important objective of underground space development. It is especially urgent if there are alternating weak layers in the base. The paper presents a practical geotechnical case of strengthening the overloaded base of a reinforced concrete foundation plate for a 25-storey residential building under construction. Combined soil piles that consist of Jet (type 1) soil concrete piles reinforced along the longitudinal axis with drilled injection piles made by electric discharge technology (EDT piles) are used as buried structures. This method of arrangement of a combined buried reinforced concrete structure is conditioned by the need to increase the load-bearing capacity of a pile in soil by two or more times.

Experimental study of the steel-concrete connection in the hybrid girder continuous rigid frame bridge

2021 ◽  
Author(s):  
Debao Chen ◽  
Qingtian Su ◽  
Zhiping Lin ◽  
Jiang Lin ◽  
Yuqiang Cai
Keyword(s):  
Bearing Capacity ◽  
Test Model ◽  
Steel Girder ◽  
Bearing Plate ◽  
Shear Design ◽  
Composite Joint ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Under Construction ◽  
Rigid Frame Bridge

<p>A composite joint connecting the steel girder and the concrete girder with the connectors of perfobond ribs and studs was applied in Anhai Bay Bridge under construction with a span of 135m+300m+135m, which will become the second-largest span of hybrid continuous rigid frame bridge in the world after completion. In this paper, the whole and partial finite element models developed to analyze the main bridge and the detailed load-bearing capacity of the steel-concrete composite joint are described. To study the failure mechanism and evaluate the bearing capacity of the steel-concrete connection, the typical concrete-filled steel cells with a reduced scale of 1:2 were chosen to be the test model. The experiment verifies that the steel-concrete connection has enough bearing capacity, which can resist the compression and shear design forces. The back bearing plate plays an important role in uniformly distributing force.</p>

Effects of Foundation Pit Dewatering on Load-bearing Capacity of Soil Body around the Pit

2011 ◽  
Vol 9 (1) ◽  
pp. 29-32
Author(s):  
Chen-guang JIANG ◽  
Kui LU ◽  
Chang-sheng LIN ◽  
Wei-nan SHI ◽  
Liang-sheng GONG
Keyword(s):  
Bearing Capacity ◽  
Load Bearing Capacity ◽  
Foundation Pit ◽  
Load Bearing

scholarly journals Horizontal Bearing Test and Optimization of m Value for Precast Piles in Alluvium Stratum of the Yellow River

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Xianzhou Lyu ◽  
Zhen Chen ◽  
Zenghui Zhao ◽  
Weiming Wang
Keyword(s):  
Bearing Capacity ◽  
Yellow River ◽  
Back Analysis ◽  
Horizontal Displacement ◽  
The Yellow River ◽  
Analysis Model ◽  
Foundation Design ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Geological Conditions

For a pile foundation design, the value of proportional coefficient m to define the soil horizontal resist force is a significant parameter. However, different geological conditions and experimental environment have led to different m values. In this paper, an in situ test is firstly carried out on the horizontal bearing capacity of large-size precast square-piles. The piles deformation is then derived by using the optimization method from the measured data. Secondly a back analysis model is established to calculate the m value by using the simplex method, which reveals the evolution rule of the value of proportional coefficient m. Results show that the horizontal bearing characteristics of precast piles depend on the interaction force of piles and soils. The action mechanism of the soils around the piles is gradually developed with the increase in the concrete content. The horizontal critical load and the Eigenvalue of horizontal bearing capacity increased by 16.7% and 20%, respectively. It is also seen that the higher the content of the cement-soil around the piles and the longer the pile length, the bigger the m value obtained. The variation of the proportional coefficient m with the horizontal displacement of pile top is defined by three stages: rapid decaying stage, slow decaying stage, and balanced stage, respectively. The inverse analysis method on the proposed m value can accurately reflect the actual working state of piles and soils. In the depth of 3~18m in the west of Ji'nan, the range of m value is recommended as 4~6.58 MN·m-4. When Δ takes 12mm, the values of m are consistent with the result from the back analysis. In summary, the obtained m value can be effectively used to guide the design of enclosure structure in the super deep foundation pit in the Yellow River alluvial stratum.

Model Test Research on Horizontal Bearing Characteristics of Close-Ended Valibale Section Pipe Pile

2014 ◽  
Vol 638-640 ◽  
pp. 475-479
Author(s):  
Qing Guang Yang ◽  
Yi Han Chen ◽  
Jie Tian ◽  
Jie Liu
Keyword(s):  
Bearing Capacity ◽  
Load Transfer ◽  
Small Diameter ◽  
Bending Moment ◽  
Horizontal Load ◽  
Foundation Pit ◽  
Pipe Pile ◽  
Diameter Pipe ◽  
Load Displacement ◽  
Constant Section

Base on indoor model tests of three variable section pipe piles and two constant section pipe piles performed in foundation pit,the load transfer mechanism of two kinds of close-ended pipe piles are studied by comparing horizontal load-displacement curves, critical load and bending moment of piles. Results show that horizontal load-displacement curves change slowly and horizontal bearing capacity of valiable section pipe piles will be higher than constant section pipe piles with equal average diameters.Comparing with constant section pipe piles 1# and 2# with equal average diameters, unit volume horizontal critical bearing capacity of 3# and 4# are improved 8.7% and 34.2% respectively and which have different degrees of increse with improvement of valiable section ratio. Moreover,there are two maximum bending moment to valialble section pipe piles insteard of one to constant section pipe piles.To pipe piles 3#,4# and 5#, maximum bending moment ratio of big diameter pipe to small diameter pipe of valiable section pipe pile are 3.13、2.33 and 1.89 respectively. To pipe piles 3# and 4#, maximum bending moments of big diameter pipe are improved 26.8% and 28.4%.Howeverm,maximum bending moment of small diameter pipe are improved 54.1% and 111.8%.So,it is very clear that valiable section pipe pile is more reasonable than constant section pipe pile in bearing characteristics.

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