Experimental Study On Reinforcement Of Loess Slope In Heifangtai Gansu

Heifangtai in Yongjing County,Gansu Province is located in the northwestern loess region.From the late 1950s to the mid-1970s,it experienced three large-scale migrations,resettling and transferring 44,000 people.In order to develop production,people built three reservoirs in Heifangtai.Due to the construction of the reservoirs,a large number of people moved here,and a water diversion and irrigation project was established to divert the Yellow River water to the plateau for agricultural production irrigation.Long-term irrigation has caused a large amount of surface water to enter the interior of the loess,and a large amount of groundwater is enriched on the top of the silty clay layer at the bottom of the loess,forming a saturated and soft loess layer,resulting in densely-covered loess landslides,farmland destruction and road interruption,which can be seen.The stability of the loess structure plays a decisive role in the lives,property and safety of residents living in the loess plateau.After reading a large number of related documents on the causes of loess slope landslides in the Heifangtai area and the current treatment methods,I learned that the rise of groundwater level and the loss of gelling substances caused by long-term irrigation are the two major causes of landslides in this area.For loess landslides in our country,early warning is still the main method,and the treatment methods still adopt more traditional methods,such as slope cutting and unloading,back pressure of filling,and anti-skid retaining walls.However,experience shows that it is difficult to carry out large-scale construction in this area,and the cost is high.The use of these methods can only make the loess landslide in a temporary stable state,and the probability of re-sliding is greater.This article applies electrochemical reinforcement technology to loess for the first time,summarizes the mechanism of electrochemical reinforcement technology,and investigates the slopes of the Heifangtai loess plateau area.The original loess sent back to the site is reshaped and the loess is made.The verification test of the feasibility of the electrokinetic chemical reinforcement method,that is,under the same test conditions,the two loess samples are added or not added with the conditioning fluid,and the water discharge of the loess during the test is observed,and the moisture content of the two soil samples decreases and decreases after the power-on.Strength increase value of soil.Research has found that electrokinetic chemical reinforcement can promote the discharge of loess water,and the added conditioning fluid will generate more gelling substances to fill the loess particles under the action of electric potential,which greatly increases the strength of the consolidated loess.Considering the influence of different test conditions on the effect of electrochemical reinforcement of loess,12 groups of loess samples under different test conditions are considered from the aspects of adjusting liquid ratio,voltage change,energizing time change and injecting adjusting liquid position.In the process of soil sample test,the current change,energy consumption increase and decrease,drainage efficiency,the decrease of water content in each area after reinforcement,and the law of soil strength change with age are comprehensively compared and analyzed,and the optimal reinforcement plan is summarized according to the test conclusions.On-site slope reinforcement provides a theoretical basis,and further verify the feasibility of electrochemical method through field test.