scholarly journals Study on the collapsibility sensitivity of loess in different acid environment by consolidometer

2021 ◽  
Vol 267 ◽  
pp. 02069
Author(s):  
Yao Zhang ◽  
Cheng Jin ◽  
Ning Li ◽  
Zaiqiang Hu
Keyword(s):  
Acidic Solution ◽  
Structural Strength ◽  
Water Solution ◽  
Test Results ◽  
Internal Factor ◽  
Loess Area ◽  
Collapsible Loess ◽  
Acid Environment ◽  
Stability Time ◽  
Sensitive Pressure

Cement connection of loess is an important internal factor of loess collapse, which has a direct impact on the sensitivity of the collapse. In this study, different concentrations of nitric acid were added into the immersion water solution of loess collapsibility test. The collapsibility deformation and stability time were measured under different pressure and acid environment. The test results show that: in acid solution, the collapsibility coefficient of collapsible loess increases more under low pressure, and the collapsibility stability time is prolonged under all levels of pressure; Loess has different collapsibility sensitive pressure range in aqueous solution and acidic solution. The structural strength of collapsible loess has an important influence on the depth of collapsible loesr. It is very important to the constructions on the loess area

scholarly journals Influence of acid environment on Collapsibility of Loess

2021 ◽  
Vol 267 ◽  
pp. 02013
Author(s):  
Yao Zhang ◽  
Cheng Jin ◽  
Zaiqiang Hu ◽  
Ning Li ◽  
Yu Xi
Keyword(s):  
Acidic Solution ◽  
Test Results ◽  
Internal Factor ◽  
Time Scanning ◽  
Collapsible Loess ◽  
Before And After ◽  
Acid Environment ◽  
Stability Time ◽  
Coefficient Stability ◽  
Sensitive Pressure

Cemented connection of loess is an important internal factor of loess collapsibility, which has a direct impact on its collapsibility. In this study, different concentrations of nitric acid were added to the immersion solution of loess collapsibility test, and the collapsibility sensitivity indexes of loess, such as collapsibility coefficient, stability time and collapsibility rate, were tested under acidic environment and different pressures. At the same time, scanning electron microscope was used to observe the changes of pore and structure of soil samples before and after the test. The test results show that in acid solution, the collapsibility coefficient of collapsible loess increases more under low pressure, and the collapsibility stability time of collapsible loess increases under different pressures. Loess has different collapsibility sensitive pressure range in aqueous solution and acidic solution. The structural strength of collapsible loess has an important influence on the depth of collapsible loess.

The Influence on Lining Moment of Tunnel under the Local Weakening of Structural Strength of Loess

2011 ◽  
Vol 250-253 ◽  
pp. 3872-3875
Author(s):  
Rong Jian Li ◽  
Wen Zheng ◽  
Juan Fang ◽  
Gao Feng Che
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Structural Strength ◽  
Numerical Results ◽  
The Finite Element Method ◽  
Loess Area ◽  
Element Method

The influence of structural strength on the lining moment of tunnel should be properly evaluated in order to meet the engineering demand in loess area. It is essential to analyze and evaluate the lining moment of tunnel by means of the finite element method under the condition of the different local weakening of structural strength in loess. Firstly, some researches on the structural strength of loess tunnel are reviewed. Then, some different cases of the local weakening of structural strength in loess are analyzed in this paper. Numerical results not only indicate that the lining moment of tunnel tends to change obviously with the different local weakening of the structural strength, but also reveal that the weakening location of structural strength has important effect on the distribution and redistribution of the lining moment of tunnel.

Application Research of Compaction Pile in Heavy Collapsible Loess

2011 ◽  
Vol 90-93 ◽  
pp. 1390-1393 ◽  
Author(s):  
Yong Qiang He ◽  
Yan Peng Zhu ◽  
Yun Wu ◽  
Xiao Qing Wang
Keyword(s):  
Soil Compaction ◽  
Composite Foundation ◽  
Application Research ◽  
Loess Area ◽  
Foundation Treatment ◽  
Collapsible Loess ◽  
Expansion Theory ◽  
Soil Compressibility ◽  
Cavity Expansion Theory ◽  
Physical Mechanics

Compaction piles is one of the conventional methods for foundation treatment in collapsible loess, there are very few research results about soil compaction effect between piles when forming the piles. Firstly, the stress field and displacement field of soil around compaction piles are elastic-plastic analyzed on the basis of the cavity expansion theory; then a series of field and laboratory tests were performed to evaluate the treatment effect of the compaction pile composite foundation. The result shows that the collapsibility has been eliminated, all physical mechanics indexes have been improved, and soil compressibility and modulus of compressibility are also increased remarkably. It embodies the correctness of the computation theory. And the feasibility of the compaction piles composite foundation on collapsible loess area is further proved.

scholarly journals Influence of Voids Ratio on Impact Behavior of Circular Ferrocement Slabs

2019 ◽  
Vol 5 (1) ◽  
pp. 117
Author(s):  
Muyasser M. Jomaah ◽  
Muna Zead Baraa
Keyword(s):  
Impact Energy ◽  
Structural Strength ◽  
Impact Load ◽  
Low Cost ◽  
Load Test ◽  
Wire Mesh ◽  
Impact Behavior ◽  
Experimental Program ◽  
Test Results ◽  
The Impact

The objective of using materials is to fully utilize the properties of these materials in order to obtain the best performance of the structure. The merits of material are based on many factors like, workability, structural strength, durability and low cost. Ferrocement is an excellent construction system. This paper studies the behavior of ferrocement circular slabs under impact load. The experimental program include testing four sime fixed supported ferrocement circular slabs of 800mm diameter and 50mm thickness. The Influence of the use of styropor voids was investigated in different ratios (24% and 48%) and a number of wire mesh layers four and six layers. Impact load test results revealed that increasing number of wire mesh from 4 to 6 led to an increase in the impact energy for first crack by (41.991% ,37.62%) respectively when using voids ratio by (24% and 48%) respectively and impact energy for full perforation by (21.7% and 9.94%) respectively when using voids ratio by (24% and 48%) respectively. Ferrocement circular slabs are used in construction fields such as roofs, tanks, manholes, etc.

scholarly journals Analysis of Vertical Load Transfer Mechanism of Assembled Lattice Diaphragm Wall in Collapsible Loess Area

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mingtan Xia ◽  
Xudong Zhang ◽  
Gengshe Yang ◽  
Liu Hui ◽  
Wanjun Ye
Keyword(s):  
Failure Modes ◽  
Load Transfer ◽  
Diaphragm Wall ◽  
Vertical Load ◽  
Soil System ◽  
Loess Area ◽  
Collapsible Loess ◽  
Negative Friction ◽  
Vertical Bearing ◽  
Soil Interface

Based on analysis of the formation mechanism and characteristics of the negative friction in collapsible loess areas, this study investigates the load transfer law of a wall-soil system under a vertical load, establishes the vertical bearing model of a lattice diaphragm wall, and analyzes the vertical bearing capacity of an assembled latticed diaphragm wall (ALDW) in a loess area. The factors influencing the vertical bearing characteristics of the ALDW in a loess area are analyzed. The vertical bearing mechanism of the lattice diaphragm wall in the loess area is investigated. The failure modes of the ALDW in the loess area are mainly shear failure of the soil around the wall and failure of the wall-soil interface. In the generation and development of negative friction, there is always a point where the relative displacement of the wall-soil interface is zero at a certain depth below the ground; at this point, the wall and soil are relative to each other. The collapsibility of loess, settlement of the wall and surrounding soil, and rate and method of immersion are the factors affecting the lattice diaphragm wall. The conclusions of this study provide a reference for the design and construction of ALDWs in loess areas.

Study of the Iron Behavior in Acid Rain Water Solution by Application of Two Green Corrosion Inhibitors

2021 ◽  
Vol 6 (1) ◽  
pp. 19
Author(s):  
Meryem Zouarhi ◽  
Said Abbout ◽  
Hind Hammouch ◽  
Mohamed Chellouli ◽  
Hamid Erramli ◽  
...  
Keyword(s):  
Corrosion Inhibitors ◽  
Inhibition Efficiency ◽  
Acidic Solution ◽  
Water Solution ◽  
Solution Ph ◽  
Environment Friendly ◽  
Ohmic Drop ◽  
Acidic Rain ◽  
Corrosion Of Iron ◽  
Green Corrosion Inhibitors

The corrosion of iron in an acidic medium similar to acid rainwater (pH = 3.6) at various rotation speeds was investigated. The investigation included the inhibiting effect of two new green formulations containing oils extracted from the seeds of Jatropha curcas (labeled JAC) and Aleurite moluccana (labeled ALM). The inhibition efficiency was evaluated using electrochemical measurements, after performing an automatic ohmic drop compensation (ZIR). The results obtained show that an increase in the rotation speed leads an increase in the current density (from 75.57 µA/cm2 at 0 rpm to 99.09 µA/cm2 at 1500 rpm). This increase can be explained by the increase in the amount of dissolved oxygen at the electrode surface in the acidic rain solution (pH = 3.6). Also, the two environment-friendly corrosion inhibitors both act as mixed type inhibitors that protect iron against corrosion in the acidic solution. The inhibition efficiency increases with an increase in the inhibitor concentration to attain a maximum of 97% and 96% at 250 ppm of the ALM and the JAC, respectively.

Evaluation of Structural Strength and Parameters of Collapsible Loess

2021 ◽  
Vol 21 (6) ◽  
pp. 04021066
Author(s):  
Lei Pan ◽  
Jun-Gao Zhu ◽  
Yuan-Fang Zhang
Keyword(s):  
Structural Strength ◽  
Collapsible Loess

A Field Experimental Study of Composite Foundation with Rammed Soil-Cement Pile in Collapsible Loess Area

2014 ◽  
Vol 1030-1032 ◽  
pp. 969-973 ◽  
Author(s):  
Hai Jian Sun ◽  
Shi You Zhang
Keyword(s):  
Composite Foundation ◽  
Engineering Properties ◽  
Test Results ◽  
Loading Test ◽  
Foundation Soil ◽  
Loess Area ◽  
Soil Cement ◽  
Static Loading Test ◽  
Natural Foundation ◽  
Field Static

Natural foundation in loess areas is collapsible; however, composite foundation with rammed soil-cement pile can be used to meet the load requirements of the building. Immersion-compression test and field static loading test were carried out to measure the treatment effect. The test results showed that: the collapsible of loess foundation can be eliminated by treatment with rammed soil-cement pile when the loading pressure is between 200 to 500 kPa. Engineering properties of the foundation soil between piles are improved. The parameters improve more obvious with the pile spacing getting smaller. The bearing capacity of composite foundation increased to 291 kPa, compared with natural loess foundation. The research results can be applied to design and construction of compacted soil cement pile composite foundation in loess area.

Sign in / Sign up

Export Citation Format

Share Document