Method and device for evaluating disaster of acid rain to lime-improved loess

Abstract

The invention relates to a method and a device for assessing the disaster of acid rain to lime-improved loess. The assessment method comprises the following steps: acquiring in-situ improved soil and in-situ loess, carrying out layered treatment, and testing; comparing various data of the in-situ improved soil and the in-situ loess after testing with various data of the initial improved soil and the initial loess after testing, and judging the degradation degree of the in-situ improved soil; a model experiment box is manufactured according to the actual working condition of the side slope, the model experiment box is sequentially filled with an in-situ loess side slope and an in-situ improved soil side slope, side slope damage of the actual working condition of the side slope under acid degradation is simulated, and the in-situ improved soil side slope and the in-situ loess side slope are obtained, subjected to layering treatment and tested; and comparing various data of the in-situ improved soil side slope and the in-situ loess side slope after testing with various data of the initial improved soil and the initial loess after testing, and judging the deterioration degree of the in-situ improved soil side slope. The design has the advantages of high reliability of evaluation results, high accuracy, convenient operation and low cost.

Description

Technical Field

[0001] The invention relates to the technical field of acidic deterioration of loess improved by lime, and in particular to a method and a device for evaluating the damage of acid rain to loess improved by lime. Background Art

[0002] Loess is mainly a sediment formed by wind and water transport and accumulation. It is usually grayish yellow to slightly reddish yellow, with characteristics such as multiple pores, strong structure, developed vertical joints and collapsibility. The geological environment of the Loess Plateau is complex, significantly affected by the geographical environment and climate, and prone to geological disasters such as landslides, earthquakes and mudslides. With the increasing number of engineering construction, loess in most areas needs to be improved and solidified to meet the needs of engineering construction. Lime improvement technology has been widely used in dealing with the problem of loess collapsibility, bringing significant improvements and advantages to engineering construction in loess areas. Loess often brings challenges in engineering due to its unique collapsibility, but the introduction of lime improvement technology has effectively solved this problem and achieved significant improvements in many aspects to better meet the actual needs of engineering.

[0003] However, with the rapid development of industry, the natural environment has also been damaged to a certain extent, and acid rain disasters have occurred frequently. Acid rain is acidic, while loess improved by lime is alkaline, and the two are prone to neutralization reaction. Since acid rain is mainly sulfuric acid rain, it is easy to react with soil improved by lime to form calcium sulfate. Therefore, the effects of the two are relatively complex, and it is difficult for existing technologies to accurately evaluate the degree of acid degradation of loess improved by lime in acid rain. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects and problems of the prior art in that lime-improved loess has poor evaluation effect on acid rain acidity degradation, and to provide a method and device for evaluating the damage of acid rain to lime-improved loess with good evaluation effect.

[0005] To achieve the above objectives, the technical solution of the present invention is: a method for evaluating the damage of acid rain to lime-improved loess, characterized in that the evaluation method comprises the following steps:

[0006] Obtain in-situ improved soil for fill reinforcement that has been damaged by acid rain and in-situ loess that has been deteriorated by acidity, carry out layered processing, and make reshaped samples of the in-situ improved soil and in-situ loess between each layer and conduct tests;

[0007] Compare the various data after testing of the in-situ improved soil used for fill reinforcement that has been damaged by acid rain and the in-situ loess that has been degraded by acidity with the various data after testing of the initial improved soil and initial loess that have not been affected by acid rain to determine the degree of degradation of the in-situ improved soil under the action of acid rain;

[0008] A model test box is made according to the actual working conditions of the slope. In-situ loess slopes and in-situ improved soil slopes are sequentially filled in the model test box to simulate the slope damage under acidic degradation caused by acid rain under the actual working conditions of the slope. In-situ improved soil slopes and in-situ loess slopes that have been damaged by acid rain are obtained and layered according to the sliding zone. The in-situ improved soil slopes and in-situ loess slopes between each layer are made into reshaped samples and tested;

[0009] The test data of the in-situ improved soil slopes that have been damaged by acid rain and the in-situ loess slopes that have been deteriorated by acidity are compared with the test data of the initial improved soil and initial loess that have not been affected by acid rain to determine the degree of degradation of the in-situ improved soil slopes under the action of acid rain.

[0010] The specific steps of determining the degree of degradation of the in-situ improved soil under the action of acid rain are:

[0011] Quantitatively change the mechanical properties of the in-situ improved soil and observe the final settlement h of the in-situ improved soil 13 , quantitatively change the physical properties of the in-situ improved soil, and observe the final settlement of the in-situ improved soil 14 , quantitatively change the chemical properties of the in-situ improved soil, and observe the final settlement of the in-situ improved soil 15 , and determine the mechanical property test influence coefficient x1, physical property test influence coefficient y1, and chemical property test influence coefficient z1 of the in-situ improved soil according to the final settlement, and calculate the evaluation coefficient K1 of the degradation degree of the in-situ improved soil under the action of acid rain;

[0012] The calculation formulas for the mechanical property test influence coefficient x1, physical property test influence coefficient y1, and chemical property test influence coefficient z1 of in-situ improved soil are as follows:

[0013]

[0014] Wherein, F is the mechanical property test and evaluation parameter of the in-situ improved soil, W is the physical property test and evaluation parameter of the in-situ improved soil, and H is the chemical property test and evaluation parameter of the in-situ improved soil;

[0015] The calculation formula of the evaluation coefficient K1 is as follows:

[0016] K1=x1×F+y1×W+z1×H;

[0017] When K1>1, it means that the improvement effect of the in-situ improved soil is enhanced by acid rain disturbance;

[0018] When 2 / 3<K1<1, it means that the in-situ improved soil is slightly acidic deteriorated;

[0019] When 1 / 3<K1<2 / 3, it means that the in-situ improved soil is moderately acidic;

[0020] When 0<K1<1 / 3, it means that the in-situ improved soil is severely acidic;

[0021] When K1<0, it means that the in-situ improved soil has been degraded by acidity and its comprehensive properties are lower than those of the in-situ loess.

[0022] The specific formula for the mechanical property test evaluation parameter F of the in-situ improved soil is:

[0023]

[0024] F = s1F1 × s2F2 × s3F3;

[0025] s1+s2+s3=1;

[0026] Among them, C1, C2, and C3 represent the cohesion of each layer of in-situ loess, They represent the internal friction angle of each layer of in-situ loess, δ1, δ2, δ3 represent the wetting coefficient of each layer of in-situ loess, C t represents the cohesion of the initial improved soil experimentally measured, represents the internal friction angle measured from the initial improved soil experiment, δ t represents the collapsibility coefficient measured by the initial improved soil experiment, C0 represents the cohesion measured by the initial loess experiment, represents the internal friction angle measured by the initial loess experiment, δ0 represents the collapsibility coefficient measured by the initial loess experiment, c1, c2, c3 represent the cohesion of each layer of in-situ improved soil in the shear strength test, They respectively represent the influence factor of the internal friction angle of each layer of in-situ improved soil in the shear strength test, p1, p2, p3 represent the influence coefficient of the shear strength of each layer of in-situ improved soil in the shear strength test, q1, q2, q3 represent the influence coefficient of the compression properties of each layer of in-situ improved soil in the compression properties test, F1, F2, F3 respectively represent the evaluation of the mechanical properties of each layer of in-situ improved soil, s1, s2, s3 respectively represent the influence coefficient of each layer of in-situ improved soil.

[0027] The specific formula for the physical property test evaluation parameter W of the in-situ improved soil is:

[0028]

[0029] s1+s2+s3=1;

[0030] Among them, ρ d-1 , d-2 , d-3They represent the dry density of each layer of in-situ loess, e1, e2, e3 represent the porosity of each layer of in-situ loess, I1, I2, I3 represent the plasticity index of each layer of in-situ loess, ρ d-t represents the dry density of the initial improved soil experimentally measured, e t represents the void ratio measured by the initial improved soil experiment, I t represents the plasticity index of the initial improved soil experimentally measured, ρ d-0 represents the dry density measured by the initial loess experiment, e0 represents the porosity ratio measured by the initial loess experiment, I0 represents the plasticity index measured by the initial loess experiment, ρ1, ρ2, ρ3 represent the dry density influence coefficient of each layer of in-situ improved soil in the physical property test, ∈1, ∈2, ∈3 represent the porosity influence coefficient of each layer of in-situ improved soil in the physical property test, i1, i2, i3 represent the plasticity index influence coefficient of each layer of in-situ improved soil in the physical property test, W1, W2, W3 represent the evaluation of the physical properties of each layer of in-situ improved soil, s1, s2, s3 represent the influence coefficient of each layer of in-situ improved soil.

[0031] The specific formula for the chemical property test evaluation parameter H of the in-situ improved soil is:

[0032]

[0033]

[0034] H=s1H1×s2H2×s3H3;

[0035] s1+s2+s3=1;

[0036] Among them, ph1, ph2, and ph3 represent the pH values ​​of the in-situ loess layers, respectively, and N SO-1 、N SO-2 、N SO-3 Represents the in-situ loess of each layer Concentration, N OH-1 、N OH-2 、N OH-3 represents the OH of each layer of in-situ loess - Concentration, N Ca-1 、N Ca-2 、N Ca-3 represents the Ca content of each layer of in-situ loess 2+ Concentration, pH t represents the pH value measured in the initial improved soil experiment, N SO-t It represents the initial improved soil experimental measurement Concentration, N OH-t represents the OH measured in the initial improved soil experiment - Concentration, N Ca-trepresents the Ca content of the initial improved soil experimentally measured 2+ concentration, ph0 represents the pH value measured in the initial loess experiment, N SO-0 It represents the initial loess test result. Concentration, N OH-0 represents the OH measured in the initial loess experiment - Concentration, N Ca-0 represents the Ca content measured in the initial loess experiment 2+ concentration, g1, g2, and g3 represent the concentration of each layer of in-situ improved soil in the chemical property test. The ion concentration influence coefficients, a1, a2, and a3 represent the OH concentration of each layer of in-situ improved soil in the chemical property test. - The ion concentration influence coefficient, o1, o2, o3 represent the Ca concentration of each layer of in-situ improved soil in the chemical property test 2+ n1, n2, n3 represent the influence coefficients of main ion concentrations of each layer of in situ improved soil in the chemical property test, p1, p2, p3 represent the influence coefficients of pH value of each layer of in situ improved soil in the chemical property test, W1, W2, W3 respectively represent the evaluation of the chemical properties of each layer of in situ improved soil, s1, s2, s3 respectively represent the influence coefficients of each layer of in situ improved soil.

[0037] The specific steps of judging the degree of degradation of the in-situ improved soil slope under the action of acid rain are:

[0038] Quantitatively change the mechanical properties of the in-situ improved soil slope and observe the ultimate bearing capacity T of the in-situ improved soil slope 14 , quantitatively change the physical properties of the in-situ improved soil slope, and observe the ultimate bearing capacity T of the in-situ improved soil slope 15 , quantitatively change the chemical properties of the in-situ improved soil slope, and observe the ultimate bearing capacity T of the in-situ improved soil slope 16 , and determine the mechanical property test influence coefficient x2, physical property test influence coefficient y2, and chemical property test influence coefficient z2 of the in-situ improved soil slope according to the ultimate bearing capacity, and calculate the evaluation coefficient K2 of the deterioration degree of the in-situ improved soil slope under the action of acid rain;

[0039] The calculation formulas for the mechanical property test influence coefficient x2, physical property test influence coefficient y2, and chemical property test influence coefficient z2 of the in-situ improved soil slope are as follows:

[0040]

[0041] Wherein, F′ is the mechanical property test and evaluation parameter of the in-situ improved soil, W′ is the physical property test and evaluation parameter of the in-situ improved soil, and H′ is the chemical property test and evaluation parameter of the in-situ improved soil;

[0042] The calculation formula of the evaluation coefficient K2 is as follows:

[0043] K2=x2×F′+y2×W′+z2×H′;

[0044] When K2>1, it means that the improvement effect of the in-situ improved soil slope is enhanced by acid rain disturbance;

[0045] When 2 / 3<K2<1, it means that the in-situ improved soil slope is slightly acidic deteriorated;

[0046] When 1 / 3<K2<2 / 3, it means that the in-situ improved soil slope is moderately acidic deteriorated;

[0047] When 0<K2<1 / 3, it means that the in-situ improved soil slope is severely acidic deteriorated;

[0048] When K2<0, it means that the in-situ improved soil slope has been deteriorated by acidity and its comprehensive properties are lower than those of the in-situ loess slope.

[0049] The specific formula for the mechanical property test evaluation parameter F' of the in-situ improved soil slope is:

[0050]

[0051]

[0052] F′=s4F4×s5F5×s6F6;

[0053] s4+s5+s6=1;

[0054] Among them, C4, C5, and C6 represent the cohesion of each layer of the in-situ loess slope, represents the internal friction angle of each layer of the in-situ loess slope, δ4, δ5, δ6 represent the collapsibility coefficient of each layer of the in-situ loess slope, C t represents the cohesion of the initial improved soil experimentally measured, represents the internal friction angle measured from the initial improved soil experiment, δ t represents the collapsibility coefficient measured from the initial improved soil experiment, C 0-4 , C 0-5 , C 0-6 They represent the cohesion of each layer of in-situ improved soil slope under slope failure, They represent the influencing factors of the internal friction angle of each layer of in-situ improved soil slope under slope failure, δ 0-4 ,δ 0-5 ,δ 0-6 They represent the collapsibility coefficients of each layer of in-situ improved soil slope under slope failure, c4, c5, c6 represent the cohesion influence coefficients of each layer of in-situ improved soil slope in shear strength test, It represents the influence coefficient of internal friction angle of each layer of in-situ improved soil slope in shear strength test, p4, p5, p6 represent the influence coefficient of shear strength of each layer of in-situ improved soil slope in shear strength test, q4, q5, q6 represent the influence coefficient of compression property of each layer of in-situ improved soil slope in compression property test, F4, F5, F6 respectively represent the evaluation of mechanical properties of each layer of in-situ improved soil slope, s4, s5, s6 respectively represent the influence coefficient of each layer of in-situ improved soil slope.

[0055] The specific formula for the physical property test evaluation parameter W' of the in-situ improved soil slope is:

[0056]

[0057] W′=s4W4×s5W5×s6W6;

[0058] s4+s5+s6=1;

[0059] Among them, ρ d-4 , d-5 , d-6 They represent the dry density of each layer of in-situ improved soil slope, e4, e5, e6 represent the void ratio of each layer of in-situ improved soil slope, I4, I5, I6 represent the plasticity index of each layer of in-situ improved soil slope, ρ d-t represents the dry density of the initial improved soil experimentally measured, e t represents the void ratio measured by the initial improved soil experiment, I t represents the plasticity index of the initial improved soil experimentally measured, ρ d-0 represents the dry density measured by the initial loess experiment, e0 represents the porosity ratio measured by the initial loess experiment, I0 represents the plasticity index measured by the initial loess experiment, ρ4, ρ5, ρ6 represent the dry density influence coefficients of each layer of in-situ improved soil slope in the physical property test, ∈4, ∈5, ∈6 represent the porosity influence coefficients of each layer of in-situ improved soil slope in the physical property test, i4, i5, i6 represent the plasticity index influence coefficients of each layer of in-situ improved soil slope in the physical property test, w4, w5, w6 represent the evaluation of the physical properties of each layer of in-situ improved soil slope, s4, s5, s6 represent the influence coefficients of each layer of in-situ improved soil slope.

[0060] The specific formula for the chemical property test evaluation parameter H' of the in-situ improved soil slope is:

[0061]

[0062] H′=s4H4×s5H5×s6H6;

[0063] s4+s5+s6=1;

[0064] Among them, ph4, ph5, and ph6 represent the pH values ​​of each layer of in-situ improved soil slope, N SO-4 、N SO-5 、N SO-6 Represents the in-situ improved soil slope of each layer Concentration, N OH-4 、N OH-5 、N OH-6 represents the OH of each layer of in-situ improved soil slope - Concentration, N Ca-4 、N Ca-5 、N Ca-6 represents the Ca of each layer of in-situ improved soil slope 2+ Concentration, pH t represents the pH value measured in the initial improved soil experiment, N SO-t It represents the initial improved soil experimental measurement Concentration, N OH-t represents the OH measured in the initial improved soil experiment - Concentration, N Ca-t represents the Ca content of the initial improved soil experimentally measured 2 + concentration, ph0 represents the pH value measured in the initial loess experiment, N SO-0 It represents the initial loess test result. Concentration, N OH-0 represents the OH measured in the initial loess experiment - Concentration, N Ca-0 represents the Ca content measured in the initial loess experiment 2+ concentration, g4, g5, and g6 represent the concentration of each layer of in-situ improved soil slope in the chemical property test. The ion concentration influence coefficients, a4, a5, and a6 represent the OH concentration of each layer of in-situ improved soil slope in the chemical property test. - The ion concentration influence coefficient of o4, o5, and o6 represent the Ca concentration of each layer of in-situ improved soil slope in the chemical property test. 2 +, n4, n5, n6 represent the influence coefficients of main ion concentrations of each layer of in situ improved soil slope in the chemical property test, p4, p5, p6 represent the influence coefficients of pH value of each layer of in situ improved soil slope in the chemical property test, H4, H5, H6 represent the evaluation of the chemical properties of each layer of in situ improved soil slope, s4, s5, s6 represent the influence coefficients of each layer of in situ improved soil slope.

[0065] A device for evaluating the damage of acid rain to lime-modified loess, the device is applied to a method for evaluating the damage of acid rain to lime-modified loess, the device comprises a model experiment box, the model experiment box is filled with in-situ loess and improved loess slope from bottom to top, a cavity is arranged between the improved loess slope and the model experiment box, a rainwater outlet connected to the cavity is opened on one side of the model experiment box, a plurality of measuring points are arranged on the upper side of the improved loess slope, a laser displacement sensor corresponding to the plurality of measuring points is arranged on the top of the model experiment box, a rainfall simulator is installed on the top of the model experiment box, a water inlet pipe and a water outlet pipe are arranged at the bottom of the model experiment box, a groundwater level detector is arranged on the inner side of the model experiment box, and a temperature controller is arranged on the outer side of the model experiment box;

[0066] The rainfall simulator is used to simulate acid rain precipitation under different conditions;

[0067] The measuring points are used to detect various data of the improved loess slope;

[0068] The laser displacement sensor is used to detect the height of the improved loess slope at the measuring point before and after rainfall.

[0069] Compared with the prior art, the present invention has the following beneficial effects:

[0070] 1. In the method and device for evaluating the damage of acid rain to lime-modified loess, the mechanical, physical and chemical properties of the improved loess are comprehensively considered to make the evaluation result more reliable. At the same time, two evaluation schemes are provided for two different working conditions, namely, improved loess for filling reinforcement and improved loess slope for improving slope stability, so as to increase the accuracy of the evaluation result. Therefore, the evaluation result of the present invention has high reliability and accuracy.

[0071] 2. In the method and device for evaluating the damage of acid rain to lime-modified loess, the reliability of the data further increases the reliability of the evaluation results by using a simulation test box for the experiment, and each test is easy to operate and has low cost. At the same time, the specific relevant influence coefficients of each layer of reshaped samples in the mechanical properties, physical properties, and chemical properties tests are all related to the actual engineering, which further enhances the reliability of the evaluation results. Therefore, the evaluation results of the present invention are highly reliable and accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 The present invention is a schematic flow chart of a method for evaluating the damage of acid rain to lime-improved loess.

[0073] Figure 2 It is a structural schematic diagram of a device for evaluating the damage of acid rain to lime-improved loess in the present invention.

[0074] Figure 3 It is a structural schematic diagram of the temperature controller in the present invention.

[0075] In the figure: model experiment box 1, in-situ loess 2, improved loess slope 3, cavity 4, rainwater outlet 5, measuring point 6, laser displacement sensor 7, rainfall simulator 8, water inlet pipe 9, water outlet pipe 10, groundwater level detector 11, temperature controller 12, temperature detector 13, control switch 14, flow rate controller 15. DETAILED DESCRIPTION

[0076] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0077] Embodiment 1:

[0078] See also Figure 1 , a method for evaluating the damage of acid rain to lime-modified loess, the method comprising the following steps:

[0079] Step 1: Obtain in-situ improved soil for fill reinforcement that has been damaged by acid rain and in-situ loess that has been deteriorated by acidity, and perform layered treatment. The in-situ improved soil and in-situ loess between each layer are made into reshaped samples and tested for mechanical properties, physical properties, and chemical properties;

[0080] Step 2: Compare the various data after testing of the in-situ improved soil used for fill reinforcement that has been damaged by acid rain and the in-situ loess that has been degraded by acidity with the various data after testing of the initial improved soil and initial loess that have not been affected by acid rain, to determine the degree of degradation of the in-situ improved soil under the action of acid rain;

[0081] Step 3: A model test box is made according to the actual working conditions of the slope, and the in-situ loess slope and the in-situ improved soil slope are sequentially filled in the model test box to simulate the slope damage under the acidic degradation of acid rain under the actual working conditions of the slope. The in-situ improved soil slope and the in-situ loess slope that have been damaged by acid rain are obtained and layered according to the sliding zone. The in-situ improved soil slope and the in-situ loess slope between each layer are made into reshaped samples for mechanical property, physical property and chemical property testing;

[0082] Step 4: Compare the test data of the in-situ improved soil slopes that have been damaged by acid rain and the in-situ loess slopes that have been degraded by acidity with the test data of the initial improved soil and initial loess that have not been affected by acid rain to determine the degree of degradation of the in-situ improved soil slopes under the action of acid rain.

[0083] In step 2, the specific steps for determining the degree of degradation of the in-situ improved soil under the action of acid rain are:

[0084] Quantitatively change the mechanical properties of the in-situ improved soil and observe the final settlement h of the in-situ improved soil 13, quantitatively change the physical properties of the in-situ improved soil, and observe the final settlement of the in-situ improved soil 14 , quantitatively change the chemical properties of the in-situ improved soil, and observe the final settlement of the in-situ improved soil 15 , and determine the mechanical property test influence coefficient x1, physical property test influence coefficient y1, and chemical property test influence coefficient z1 of the in-situ improved soil according to the final settlement, and calculate the evaluation coefficient K1 of the degradation degree of the in-situ improved soil under the action of acid rain;

[0085] The calculation formulas for the mechanical property test influence coefficient x1, physical property test influence coefficient y1, and chemical property test influence coefficient z1 of in-situ improved soil are as follows:

[0086]

[0087] Wherein, F is the mechanical property test and evaluation parameter of the in-situ improved soil, W is the physical property test and evaluation parameter of the in-situ improved soil, and H is the chemical property test and evaluation parameter of the in-situ improved soil;

[0088] The calculation formula of the evaluation coefficient K1 is as follows:

[0089] K1=x1×F+y1×W+z1×H;

[0090] When K1>1, it means that the improvement effect of the in-situ improved soil is enhanced by acid rain disturbance;

[0091] When 2 / 3<K1<1, it means that the in-situ improved soil is slightly acidic deteriorated;

[0092] When 1 / 3<K1<2 / 3, it means that the in-situ improved soil is moderately acidic;

[0093] When 0<K1<1 / 3, it means that the in-situ improved soil is severely acidic deteriorated;

[0094] When K1 < 0, it means that the in-situ improved soil has been degraded by acidity and its comprehensive properties are lower than those of the in-situ loess;

[0095] In step 4, the specific steps for determining the degree of degradation of the in-situ improved soil slope under the action of acid rain are:

[0096] Quantitatively change the mechanical properties of the in-situ improved soil slope and observe the ultimate bearing capacity T of the in-situ improved soil slope 14 , quantitatively change the physical properties of the in-situ improved soil slope, and observe the ultimate bearing capacity T of the in-situ improved soil slope 15 , quantitatively change the chemical properties of the in-situ improved soil slope, and observe the ultimate bearing capacity T of the in-situ improved soil slope 16, and determine the mechanical property test influence coefficient x2, physical property test influence coefficient y2, and chemical property test influence coefficient z2 of the in-situ improved soil slope according to the ultimate bearing capacity, and calculate the evaluation coefficient K2 of the deterioration degree of the in-situ improved soil slope under the action of acid rain;

[0097] The calculation formulas for the mechanical property test influence coefficient x2, physical property test influence coefficient y2, and chemical property test influence coefficient z2 of the in-situ improved soil slope are as follows:

[0098]

[0099] Wherein, F′ is the mechanical property test and evaluation parameter of the in-situ improved soil, W′ is the physical property test and evaluation parameter of the in-situ improved soil, and H′ is the chemical property test and evaluation parameter of the in-situ improved soil;

[0100] The calculation formula of the evaluation coefficient K2 is as follows:

[0101] K2=x2×F′+y2×W′+z2×H′;

[0102] When K2>1, it means that the improvement effect of the in-situ improved soil slope is enhanced by acid rain disturbance;

[0103] When 2 / 3<K2<1, it means that the in-situ improved soil slope is slightly acidic deteriorated;

[0104] When 1 / 3<K2<2 / 3, it means that the in-situ improved soil slope is moderately acidic deteriorated;

[0105] When 0<K2<1 / 3, it means that the in-situ improved soil slope is severely acidic deteriorated;

[0106] When K2<0, it means that the in-situ improved soil slope has been deteriorated by acidity and its comprehensive properties are lower than those of the in-situ loess slope.

[0107] In this embodiment, for the improved soil used for fill reinforcement that has been damaged by acid rain, the soil drilling method is used to obtain the drill core soil, which is processed in multiple layers according to needs and it is considered that the changes in various related properties in each layer are proportional to the changes in the final settlement. This paper takes three layers as an example for analysis and is marked as shallow, middle and deep layers respectively; for the improved soil used to improve the stability of the slope that has been damaged by acid rain, the soil layers above the sliding zone, the sliding zone and the sliding zone are respectively taken to make reshaped samples to study the properties of each item (it can be processed in multiple layers according to needs and it is considered that the changes in related properties in each layer are proportional to the changes in the ultimate bearing capacity of the slope. This paper treats it as three layers), and then the in-situ loess slope after acid deterioration is taken and the soil drilling method is used to obtain the drill core soil, which is proportionally enlarged according to the model experiment results and divided into three layers, recorded as the upper sliding zone layer, the sliding zone layer and the lower sliding zone layer.

[0108] Embodiment 2:

[0109] The basic content is the same as that of Example 1, except that:

[0110] In step 2, the specific formula for the mechanical property test evaluation parameter F of the in-situ improved soil is:

[0111]

[0112] F = s1F1 × s2F2 × s3F3;

[0113] s1+s2+s3=1;

[0114] Among them, C1, C2, and C3 represent the cohesion of each layer of in-situ loess, They represent the internal friction angle of each layer of in-situ loess, δ1, δ2, δ3 represent the wetting coefficient of each layer of in-situ loess, C t represents the cohesion of the initial improved soil experimentally measured, represents the internal friction angle measured from the initial improved soil experiment, δ t represents the collapsibility coefficient measured by the initial improved soil experiment, C0 represents the cohesion measured by the initial loess experiment, represents the internal friction angle measured by the initial loess experiment, δ0 represents the collapsibility coefficient measured by the initial loess experiment, c1, c2, c3 represent the cohesion of each layer of in-situ improved soil in the shear strength test, They respectively represent the influence factor of the internal friction angle of each layer of in-situ improved soil in the shear strength test, p1, p2, p3 represent the influence coefficient of the shear strength of each layer of in-situ improved soil in the shear strength test, q1, q2, q3 represent the influence coefficient of the compression properties of each layer of in-situ improved soil in the compression properties test, F1, F2, F3 respectively represent the evaluation of the mechanical properties of each layer of in-situ improved soil, s1, s2, s3 respectively represent the influence coefficient of each layer of in-situ improved soil.

[0115] In this embodiment, since the backfill reinforcement is to solve the settlement problem, the settlement of each layer of soil can be calculated and superimposed according to the basic assumption of the layered summation method, so the influence coefficient of each layer of soil is equal, that is, s1=s2=s3. Shear strength test and compression property test are carried out for the mechanical properties of the in-situ improved soil, where p1+q1=1, p2+q2=1, p3+q3=1, c1, c2, c3 and The method to determine is:

[0116] In shallow soil, the final settlement h1 is observed after quantitatively changing the cohesion C of the in-situ improved soil, and the final settlement h2 is observed after quantitatively changing the internal friction angle φ of the in-situ improved soil. The cohesion influence coefficient c1 in shear strength and the internal friction angle influence coefficient in shear strength are They are:

[0117]

[0118] c2, c3 and The method of determining is the same as above;

[0119] Among them, the determination method of p1, p2, p3 and q1, q2, q3 is:

[0120] In shallow soil, quantitatively change the shear strength τ of the in-situ improved soil (i.e., change the cohesion C and the internal friction angle φ according to the above ratio at the same time and then observe the final settlement h3, quantitatively change the collapsibility coefficient δ and then observe the final settlement h 45 , the influence coefficient p1 of shear strength in mechanical property test and the influence coefficient q1 of compression property in mechanical property test are:

[0121]

[0122]

[0123] The method for determining p2, p3 and q2, q3 is the same as above.

[0124] Embodiment 3:

[0125] The basic content is the same as that of Example 1, except that:

[0126] In step 2, the specific formula for the physical property test evaluation parameter W of the in-situ improved soil is:

[0127]

[0128] W = s1W1 × s2W2 × s3W3;

[0129] s1+s2+s3=1;

[0130] Among them, ρ d-1 , d-2 , d-3 They represent the dry density of each layer of in-situ loess, e1, e2, e3 represent the porosity of each layer of in-situ loess, I1, I2, I3 represent the plasticity index of each layer of in-situ loess, ρ d-t represents the dry density of the initial improved soil experimentally measured, e t represents the void ratio measured by the initial improved soil experiment, I trepresents the plasticity index of the initial improved soil experimentally measured, ρ d-0 represents the dry density measured by the initial loess experiment, e0 represents the porosity ratio measured by the initial loess experiment, I0 represents the plasticity index measured by the initial loess experiment, ρ1, ρ2, ρ3 represent the dry density influence coefficient of each layer of in-situ improved soil in the physical property test, ∈1, ∈2, ∈3 represent the porosity influence coefficient of each layer of in-situ improved soil in the physical property test, i1, i2, i3 represent the plasticity index influence coefficient of each layer of in-situ improved soil in the physical property test, W1, W2, W3 represent the evaluation of the physical properties of each layer of in-situ improved soil, s1, s2, s3 represent the influence coefficient of each layer of in-situ improved soil.

[0131] In this embodiment, dry density test, void ratio test and plasticity index test are performed on the physical properties of the in-situ improved soil, wherein ρ1+∈1+i1=1, ρ2+∈2+i2=1, ρ3+∈3+i3=1, and the determination method of ρ1, ρ2, ρ3, ∈1, ∈2, ∈3 and i1, i2, i3 is:

[0132] In shallow soil, the final settlement h5 is observed after quantitatively changing the dry density ρ of the soil sample, the final settlement h6 is observed after quantitatively changing the porosity e of the soil sample, and the final settlement h7 is observed after quantitatively changing the plasticity index i of the soil sample. In the physical property test, the dry density influence coefficient ρ1, the porosity influence coefficient ∈1, and the plasticity index influence coefficient i1 are respectively:

[0133]

[0134] The method for determining ρ2, ρ3, ∈2, ∈3, i2, and i3 is the same as above.

[0135] Embodiment 4:

[0136] The basic content is the same as that of Example 1, except that:

[0137] In step 2, the specific formula for the chemical property test evaluation parameter H of the in-situ improved soil is:

[0138]

[0139]

[0140] H=s1H1×s2H2×s3H3;

[0141] s1+s2+s3=1;

[0142] Among them, ph1, ph2, and ph3 represent the pH values ​​of the in-situ loess layers, respectively, and N SO-1 、N SO-2 、N SO-3Represents the in-situ loess of each layer Concentration, N OH-1 、N OH-2 、N OH-3 represents the OH of each layer of in-situ loess - Concentration, N Ca-1 、N Ca-2 、N Ca-3 represents the Ca content of each layer of in-situ loess 2+ Concentration, pH t represents the pH value measured in the initial improved soil experiment, N SO-t It represents the initial improved soil experimental measurement Concentration, N OH-t represents the OH measured in the initial improved soil experiment - Concentration, N Ca-t represents the Ca content of the initial improved soil experimentally measured 2+ concentration, ph0 represents the pH value measured in the initial loess experiment, N SO-0 The initial loess test results are Concentration, N OH-0 represents the OH measured in the initial loess experiment - Concentration, N Ca-0 represents the Ca content measured in the initial loess experiment 2+ concentration, g1, g2, and g3 represent the concentration of each layer of in-situ improved soil in the chemical property test. The ion concentration influence coefficients, a1, a2, and a3 represent the OH concentration of each layer of in-situ improved soil in the chemical property test. - The ion concentration influence coefficient, o1, o2, o3 represent the Ca concentration of each layer of in-situ improved soil in the chemical property test 2+ n1, n2, n3 represent the influence coefficients of main ion concentrations of each layer of in situ improved soil in the chemical property test, p1, p2, p3 represent the influence coefficients of pH value of each layer of in situ improved soil in the chemical property test, W1, W2, W3 respectively represent the evaluation of the chemical properties of each layer of in situ improved soil, s1, s2, s3 respectively represent the influence coefficients of each layer of in situ improved soil.

[0143] In this embodiment, pH test and main ion concentration test were performed on the chemical properties of the in-situ improved soil. The main ions included OH - , Ca 2 +、 Among them, g1+a1+o1=1, g2+a2+o2=1, g3+a3+o3=1, p1+n1=1, p2+n2=1, p3+n3=1, and the method for determining g1, g2, g3, a1, a2, a3, o1, o2, o3 is:

[0144] Quantitatively change the OH content of soil samples- After the ion concentration N1 is reached, the final settlement h8 is observed, and the Ca content of the soil sample is quantitatively changed. 2+ After the ion concentration N2 is increased, the final settlement h9 is observed, and the quantitative change of the soil sample After the ion concentration N3 is reached, the final sedimentation volume h is observed 10 In the main ion concentration test, OH - , Ca 2 +、 The influence coefficients are:

[0145]

[0146] The method of determining g2, g3, a2, a3, o2, and o3 is the same as above;

[0147] Among them, the determination method of n1, n2, n3 and p1, p2, p3 is:

[0148] Quantitatively change the pH value p of the in-situ improved soil and then observe the final settlement h 11 Quantitatively change the main ion concentration N of the soil sample (i.e., change OH at the same time according to the above ratio) - , Ca 2+ , ion concentration) and then observe the final sedimentation volume h 12 In the chemical property test, the influence coefficient p1 of pH value and the influence coefficient n1 of main ion concentration are:

[0149]

[0150] The method for determining n2, n3 and p2, p3 is the same as above.

[0151] Embodiment 5:

[0152] The basic content is the same as that of Example 1, except that:

[0153] In step 4, the specific formula of the mechanical property test evaluation parameter F' of the in-situ improved soil slope is:

[0154]

[0155] F′=s4F4×s5F5×s6F6;

[0156] s4+s5+s6=1;

[0157] Among them, C4, C5, and C6 represent the cohesion of each layer of the in-situ loess slope, represents the internal friction angle of each layer of the in-situ loess slope, δ4, δ5, δ6 represent the collapsibility coefficient of each layer of the in-situ loess slope, Ct represents the cohesion of the initial improved soil experimentally measured, represents the internal friction angle measured from the initial improved soil experiment, δ t represents the collapsibility coefficient measured from the initial improved soil experiment, C 0-4 , C 0-5 , C 0-6 They represent the cohesion of each layer of in-situ improved soil slope under slope failure, They represent the influencing factors of the internal friction angle of each layer of in-situ improved soil slope under slope failure, δ 0-4 ,δ 0-5 ,δ 0-6 They represent the collapsibility coefficients of each layer of in-situ improved soil slope under slope failure, c4, c5, c6 represent the cohesion influence coefficients of each layer of in-situ improved soil slope in shear strength test, It represents the influence coefficient of internal friction angle of each layer of in-situ improved soil slope in shear strength test, p4, p5, p6 represent the influence coefficient of shear strength of each layer of in-situ improved soil slope in shear strength test, q4, q5, q6 represent the influence coefficient of compression property of each layer of in-situ improved soil slope in compression property test, F4, F5, F6 respectively represent the evaluation of mechanical properties of each layer of in-situ improved soil slope, s4, s5, s6 respectively represent the influence coefficient of each layer of in-situ improved soil slope.

[0158] In this embodiment, the method for determining s4, s5, and s6 is:

[0159] After quantitatively changing all relevant properties of the reshaped soil sample in the upper layer of the sliding zone A1 (i.e., changing the mechanical properties, physical properties and chemical properties at the same time according to the proportions described below), the ultimate bearing capacity T1 of the in-situ improved soil slope is observed; after quantitatively changing all relevant properties of the soil sample in the sliding zone A2 (i.e., changing the mechanical properties, physical properties and chemical properties at the same time according to the proportions described below), the ultimate bearing capacity T2 of the in-situ improved soil slope is observed; after quantitatively changing all relevant properties of the soil sample in the lower layer of the sliding zone A3 (i.e., changing the mechanical properties, physical properties and chemical properties at the same time according to the proportions described below), the ultimate bearing capacity T3 of the in-situ improved slope is observed. Then, the influence coefficient s4 of the upper layer of the sliding zone, the influence coefficient s5 of the upper layer of the sliding zone, and the influence coefficient s6 of the lower layer of the sliding zone are:

[0160]

[0161] Shear strength test and compression property test were carried out on the mechanical properties of the in-situ improved soil slope. p4+q4=1, p5+q5=1, p6+q6=1, in the upper soil of the sliding zone, after quantitatively changing the cohesion C', the ultimate bearing capacity T4 of the in-situ improved soil slope is observed, after quantitatively changing the internal friction angle φ', the ultimate bearing capacity T5 of the slope is observed, after quantitatively changing the shear strength τ' (that is, after changing the cohesion C' and the internal friction angle φ' at the same time according to the above proportion, the ultimate bearing capacity T6 of the slope is observed, after quantitatively changing the collapsibility coefficient δ', the ultimate bearing capacity T7 of the slope is observed, c4, The method for determining p4 and q4 is:

[0162]

[0163]

[0164] c5, c6, The method for determining p5, p6, q5, and q6 is the same as above.

[0165] Embodiment 6:

[0166] The basic content is the same as that of Example 1, except that:

[0167] In step 4, the specific formula for the physical property test evaluation parameter W' of the in-situ improved soil slope is:

[0168]

[0169] W′=s4W4×s6W5×s6W6;

[0170] s4+s5+s6=1;

[0171] Among them, ρ d-4 , d-5 , d-6 They represent the dry density of each layer of in-situ improved soil slope, e4, e5, e6 represent the void ratio of each layer of in-situ improved soil slope, I4, I5, I6 represent the plasticity index of each layer of in-situ improved soil slope, ρ d-t represents the dry density of the initial improved soil experimentally measured, e t represents the void ratio measured by the initial improved soil experiment, I t represents the plasticity index of the initial improved soil experimentally measured, ρ d-0represents the dry density measured by the initial loess experiment, e0 represents the porosity ratio measured by the initial loess experiment, I0 represents the plasticity index measured by the initial loess experiment, ρ4, ρ5, ρ6 represent the dry density influence coefficients of each layer of in-situ improved soil slope in the physical property test, ∈4, ∈5, ∈6 represent the porosity influence coefficients of each layer of in-situ improved soil slope in the physical property test, i4, i5, i6 represent the plasticity index influence coefficients of each layer of in-situ improved soil slope in the physical property test, W4, W5, W6 represent the evaluation of the physical properties of each layer of in-situ improved soil slope, s4, s5, s6 represent the influence coefficients of each layer of in-situ improved soil slope.

[0172] In this embodiment, dry density test, void ratio test and plasticity index test are performed on the physical properties of the in-situ improved soil slope, wherein ρ4+∈4+i4=1, ρ5+∈5+i5=1, ρ6+∈6+i6=1, the ultimate bearing capacity T6 of the in-situ improved soil slope is observed after quantitatively changing the dry density ρ′ of the soil sample, the ultimate bearing capacity T7 of the slope is observed after quantitatively changing the void ratio e′ of the soil sample, and the ultimate bearing capacity T8 of the slope is observed after quantitatively changing the plasticity index i′ of the soil sample. The determination methods of ρ4, ∈4 and i4 are respectively:

[0173]

[0174] The method for determining ρ5, ρ6, ∈5, ∈6, i5, and i6 is the same as above.

[0175] Embodiment 7:

[0176] The basic content is the same as that of Example 1, except that:

[0177] In step 4, the specific formula for the chemical property test evaluation parameter H' of the in-situ improved soil slope is:

[0178]

[0179] H′=s4H4×s5H5×s6H6;

[0180] s4+s5+s6=1;

[0181] Among them, ph4, ph5, and ph6 represent the pH values ​​of each layer of in-situ improved soil slope, N SO-4 、N SO-5 、N SO-6 Represents the in-situ improved soil slope of each layer Concentration, N OH-4 、N OH-5 、N OH-6 represents the OH of each layer of in-situ improved soil slope - Concentration, N Ca-4、N Ca-5 、N Ca-6 represents the Ca of each layer of in-situ improved soil slope 2+ Concentration, pH t represents the pH value measured in the initial improved soil experiment, N SO-t It represents the initial improved soil experimental measurement Concentration, N OH-t represents the OH measured in the initial improved soil experiment - Concentration, N Ca-t represents the Ca content of the initial improved soil experimentally measured 2+ concentration, ph0 represents the pH value measured in the initial loess experiment, N SO-0 It represents the initial loess test result. Concentration, N OH-0 represents the OH measured in the initial loess experiment - Concentration, N Ca-0 represents the Ca content measured in the initial loess experiment 2+ concentration, g4, g5, and g6 represent the concentration of each layer of in-situ improved soil slope in the chemical property test. The ion concentration influence coefficients, a4, a5, and a6 represent the OH concentration of each layer of in-situ improved soil slope in the chemical property test. - The ion concentration influence coefficient of o4, o5, and o6 represent the Ca concentration of each layer of in-situ improved soil slope in the chemical property test. 2+ n4, n5, n6 represent the influence coefficients of main ion concentrations of each layer of in situ improved soil slope in the chemical property test, p4, p5, p6 represent the influence coefficients of pH value of each layer of in situ improved soil slope in the chemical property test, H4, H5, H6 represent the evaluation of the chemical properties of each layer of in situ improved soil slope, s4, s5, s6 represent the influence coefficients of each layer of in situ improved soil slope.

[0182] In this embodiment, pH test and main ion concentration test were carried out for the chemical properties of the in-situ improved soil slope. The main ions included OH - , Ca 2+ , Among them, g4+a4+o4=1, g5+a5+o5=1, g6+a6+o6=1, p4+n4=1, p5+n5=1, p6+n6=1, quantitatively changing the OH of the soil sample - After the ion concentration N4 was observed, the ultimate bearing capacity T9 was quantitatively changed. 2+ The ultimate bearing capacity T after the ion concentration N5 is observed 10 , quantitatively change the soil sample The ultimate bearing capacity T after the ion concentration N6 is observed 11 In the main ion concentration test, g4, a4, and s4 are:

[0183]

[0184] The method for determining g5, g6, a5, a6, o5, and o6 is the same as above;

[0185] Quantitatively change the pH value P′ of the in-situ improved soil and observe the ultimate bearing capacity T 12 Quantitatively change the main ion concentration N' of the soil sample (i.e., change OH at the same time according to the above ratio) - , Ca 2+ , The ultimate bearing capacity T 13 In the chemical property test, the influence coefficient n4 of pH value and the influence coefficient p4 of main ion concentration are:

[0186]

[0187] The method for determining n5, n6 and p5, p6 is the same as above.

[0188] Embodiment 8:

[0189] See also Figure 2 and Figure 3 , a device for evaluating the damage of acid rain to lime-modified loess, the device is applied to a method for evaluating the damage of acid rain to lime-modified loess in Example 1, the device comprises a model test box 1, the model test box 1 is filled with in-situ loess 2 and improved loess slope 3 from bottom to top, a cavity 4 is arranged between the improved loess slope 3 and the model test box 1, a rainwater outlet 5 connected to the cavity 4 is opened on one side of the model test box 1, a plurality of measuring points 6 are arranged on the upper side of the improved loess slope 3, a laser displacement sensor 7 corresponding to the plurality of measuring points 6 is arranged on the top of the model test box 1, a rainfall simulator 8 is installed on the top of the model test box 1, a water inlet pipe 9 and a water outlet pipe 10 are arranged at the bottom of the model test box 1, a groundwater level detector 11 is arranged on the inner side of the model test box 1, and a temperature controller 12 is arranged on the outer side of the model test box 1;

[0190] The rainfall simulator 8 is used to simulate acid rain precipitation under different conditions;

[0191] The measuring point 6 is used to detect various data of the improved loess slope 3;

[0192] The laser displacement sensor 7 is used to detect the height of the improved loess slope 3 at the measuring point 6 before and after rainfall.

[0193] In this embodiment, a temperature detector 13 is provided on the inner side of the model experiment box 1 for detecting the temperature inside the model experiment box 1. The temperature controller 12 is set as a pipe passing through the outer wall of the model experiment box 1. The temperature inside the model experiment box 1 is controlled by injecting water of different temperatures into the pipe. The water inlet pipe 9 and the water outlet pipe 10 simulate different groundwater levels through the control switch 14 in combination with the groundwater level detector 11. The rainfall simulator 8 controls the water flow rate through the flow rate controller 15 to simulate precipitation under different conditions. The above design can simulate the soil layer in special areas.

Claims

1. A method for evaluating the damage of acid rain to lime-improved loess, characterized in that: The evaluation method comprises the following steps: Obtain in-situ improved soil for fill reinforcement that has been damaged by acid rain and in-situ loess that has been deteriorated by acidity, carry out layered processing, and make reshaped samples of the in-situ improved soil and in-situ loess between each layer and conduct tests; Compare the various data after testing of the in-situ improved soil used for fill reinforcement that has been damaged by acid rain and the in-situ loess that has been degraded by acidity with the various data after testing of the initial improved soil and initial loess that have not been affected by acid rain to determine the degree of degradation of the in-situ improved soil under the action of acid rain; A model test box is made according to the actual working conditions of the slope. In-situ loess slopes and in-situ improved soil slopes are sequentially filled in the model test box to simulate the slope damage under acidic degradation caused by acid rain under the actual working conditions of the slope. In-situ improved soil slopes and in-situ loess slopes that have been damaged by acid rain are obtained and layered according to the sliding zone. The in-situ improved soil slopes and in-situ loess slopes between each layer are made into reshaped samples and tested; The test data of the in-situ improved soil slopes that have been damaged by acid rain and the in-situ loess slopes that have been deteriorated by acidity are compared with the test data of the initial improved soil and initial loess that have not been affected by acid rain to determine the degree of degradation of the in-situ improved soil slopes under the action of acid rain.

2. The method for evaluating the damage of acid rain to lime-improved loess according to claim 1, characterized in that: The specific steps of determining the degree of degradation of the in-situ improved soil under the action of acid rain are: Quantitatively change the mechanical properties of the in-situ improved soil and observe the final settlement h of the in-situ improved soil 13 , quantitatively change the physical properties of the in-situ improved soil, and observe the final settlement of the in-situ improved soil 14 , quantitatively change the chemical properties of the in-situ improved soil, and observe the final settlement of the in-situ improved soil 15 , and determine the mechanical property test influence coefficient x1, physical property test influence coefficient y1, and chemical property test influence coefficient z1 of the in-situ improved soil according to the final settlement, and calculate the evaluation coefficient K1 of the degradation degree of the in-situ improved soil under the action of acid rain; The calculation formulas for the mechanical property test influence coefficient x1, physical property test influence coefficient y1, and chemical property test influence coefficient z1 of in-situ improved soil are as follows: Wherein, F is the mechanical property test and evaluation parameter of the in-situ improved soil, W is the physical property test and evaluation parameter of the in-situ improved soil, and H is the chemical property test and evaluation parameter of the in-situ improved soil; The calculation formula of the evaluation coefficient K1 is as follows: K1=x1×F+y1×W+z1×H; When K1>1, it means that the improvement effect of the in-situ improved soil is enhanced by acid rain disturbance; When 2 / 3<K1<1, it means that the in-situ improved soil is slightly acidic deteriorated; When 1 / 3<K1<2 / 3, it means that the in-situ improved soil is moderately acidic; When 0<K1<1 / 3, it means that the in-situ improved soil is severely acidic; When K1<0, it means that the in-situ improved soil has been degraded by acidity and its comprehensive properties are lower than those of the in-situ loess.

3. The method for evaluating the damage of acid rain to lime-improved loess according to claim 2, characterized in that: The specific formula for the mechanical property test evaluation parameter F of the in-situ improved soil is: F = s1F1 × s2F2 × s3F3; s1+s2+s3=1; Among them, C1, C2, and C3 represent the cohesion of each layer of in-situ loess, They represent the internal friction angle of each layer of in-situ loess, δ1, δ2, δ3 represent the wetting coefficient of each layer of in-situ loess, C t represents the cohesion of the initial improved soil experimentally measured, represents the internal friction angle measured from the initial improved soil experiment, δ t represents the collapsibility coefficient measured by the initial improved soil experiment, C0 represents the cohesion measured by the initial loess experiment, represents the internal friction angle measured by the initial loess experiment, δ represents the collapsibility coefficient measured by the initial loess experiment, c1, c2, c3 represent the cohesion of each layer of in-situ improved soil in the shear strength test, They respectively represent the influence factor of the internal friction angle of each layer of in-situ improved soil in the shear strength test, p1, p2, p3 represent the influence coefficient of the shear strength of each layer of in-situ improved soil in the shear strength test, q1, q2, q3 represent the influence coefficient of the compression properties of each layer of in-situ improved soil in the compression properties test, F1, F2, F3 respectively represent the evaluation of the mechanical properties of each layer of in-situ improved soil, s1, s2, s3 respectively represent the influence coefficient of each layer of in-situ improved soil.

4. The method for evaluating the damage of acid rain to lime-improved loess according to claim 2, characterized in that: The specific formula for the physical property test evaluation parameter W of the in-situ improved soil is: E = s1W1 × s2W2 × s3W3; s1+s2+s3=1; Among them, ρ d-1 , d-2 , d-3 They represent the dry density of each layer of in-situ loess, e1, e2, e3 represent the porosity of each layer of in-situ loess, I1, I2, I3 represent the plasticity index of each layer of in-situ loess, ρ d-t represents the dry density of the initial improved soil experimentally measured, e t represents the void ratio measured by the initial improved soil experiment, I t represents the plasticity index of the initial improved soil experimentally measured, ρ d-0 represents the dry density measured by the initial loess experiment, e0 represents the porosity measured by the initial loess experiment, I0 represents the plasticity index measured by the initial loess experiment, p1, p2, p3 represent the dry density influence coefficient of each layer of in-situ improved soil in the physical property test, ∈1, ∈2, ∈3 represent the porosity influence coefficient of each layer of in-situ improved soil in the physical property test, i1, i2, i3 represent the plasticity index influence coefficient of each layer of in-situ improved soil in the physical property test, W1, W2, W3 represent the evaluation of the physical properties of each layer of in-situ improved soil, s1, s2, s3 represent the influence coefficient of each layer of in-situ improved soil.

5. The method for evaluating the damage of acid rain to lime-improved loess according to claim 2, characterized in that: The specific formula for the chemical property test evaluation parameter H of the in-situ improved soil is: H=s1H1×s2H2×s3H3; s1+s2+s3=1; Among them, ph1, ph2, and ph3 represent the pH values ​​of the in-situ loess layers, respectively, and N SO-1 、N SO-2 、N SO-3 Represents the in-situ loess of each layer Concentration, N OH-1 、N OH-2 、N OH-3 represents the OH of each layer of in-situ loess - Concentration, N Ca-1 、N Ca-2 、N Ca-3 represents the Ca content of each layer of in-situ loess 2+ Concentration, pH t represents the pH value measured in the initial improved soil experiment, N SO-t It represents the initial improved soil experimental measurement Concentration, N OH-t represents the OH measured in the initial improved soil experiment - Concentration, N Ca-t represents the Ca content of the initial improved soil experimentally measured 2+ concentration, ph0 represents the pH value measured in the initial loess experiment, N SO-0 It represents the initial loess test result. Concentration, N OH-0 represents the OH measured in the initial loess experiment - Concentration, N Ca-0 represents the Ca content measured in the initial loess experiment 2+ concentration, g1, g2, and g3 represent the concentration of each layer of in-situ improved soil in the chemical property test. The ion concentration influence coefficients, a1, a2, and a3 represent the OH concentration of each layer of in-situ improved soil in the chemical property test. - The ion concentration influence coefficient, o1, o2, o3 represent the Ca concentration of each layer of in-situ improved soil in the chemical property test 2+ n1, n2, n3 represent the influence coefficients of main ion concentrations of each layer of in situ improved soil in the chemical property test, p1, p2, p3 represent the influence coefficients of pH value of each layer of in situ improved soil in the chemical property test, W1, W2, W3 respectively represent the evaluation of the chemical properties of each layer of in situ improved soil, s1, s2, s3 respectively represent the influence coefficients of each layer of in situ improved soil.

6. The method for evaluating the damage of acid rain to lime-improved loess according to claim 1, characterized in that: The specific steps of judging the degree of degradation of the in-situ improved soil slope under the action of acid rain are: Quantitatively change the mechanical properties of the in-situ improved soil slope and observe the ultimate bearing capacity T of the in-situ improved soil slope 14 , quantitatively change the physical properties of the in-situ improved soil slope, and observe the ultimate bearing capacity T of the in-situ improved soil slope 15 , quantitatively change the chemical properties of the in-situ improved soil slope, and observe the ultimate bearing capacity T of the in-situ improved soil slope 16 , and determine the mechanical property test influence coefficient x2, physical property test influence coefficient y2, and chemical property test influence coefficient z2 of the in-situ improved soil slope according to the ultimate bearing capacity, and calculate the evaluation coefficient K2 of the deterioration degree of the in-situ improved soil slope under the action of acid rain; The calculation formulas for the mechanical property test influence coefficient x2, physical property test influence coefficient y2, and chemical property test influence coefficient z2 of the in-situ improved soil slope are as follows: Wherein, F′ is the mechanical property test and evaluation parameter of the in-situ improved soil, W′ is the physical property test and evaluation parameter of the in-situ improved soil, and H′ is the chemical property test and evaluation parameter of the in-situ improved soil; The calculation formula of the evaluation coefficient K2 is as follows: K2=x2×F′+y2×W′+z2×H′; When K2>1, it means that the improvement effect of the in-situ improved soil slope is enhanced by acid rain disturbance; When 2 / 3<K2<1, it means that the in-situ improved soil slope is slightly acidic deteriorated; When 1 / 3<K2<2 / 3, it means that the in-situ improved soil slope is moderately acidic deteriorated; When 0<K2<1 / 3, it means that the in-situ improved soil slope is severely acidic deteriorated; When K2<0, it means that the in-situ improved soil slope has been deteriorated by acidity and its comprehensive properties are lower than those of the in-situ loess slope.

7. The method for evaluating the damage of acid rain to lime-improved loess according to claim 6, characterized in that: The specific formula for the mechanical property test evaluation parameter F' of the in-situ improved soil slope is: F′=s4F4×s5F5×s6F6; s4+s5+s6=1; Among them, C4, C5, and C6 represent the cohesion of each layer of the in-situ loess slope, represents the internal friction angle of each layer of the in-situ loess slope, δ4, δ5, δ6 represent the collapsibility coefficient of each layer of the in-situ loess slope, C t represents the cohesion of the initial improved soil experimentally measured, represents the internal friction angle measured from the initial improved soil experiment, δ t represents the collapsibility coefficient measured from the initial improved soil experiment, C 0-4 , C 0-5 , C 0-6 They represent the cohesion of each layer of in-situ improved soil slope under slope failure, They represent the influencing factors of the internal friction angle of each layer of in-situ improved soil slope under slope failure, δ 0-4 , δ 0-5 , δ 0-6 They represent the collapsibility coefficients of each layer of in-situ improved soil slope under slope failure, c4, c5, c6 represent the cohesion influence coefficients of each layer of in-situ improved soil slope in shear strength test, It represents the influence coefficient of internal friction angle of each layer of in-situ improved soil slope in shear strength test, p4, p5, p6 represent the influence coefficient of shear strength of each layer of in-situ improved soil slope in shear strength test, q4, q5, q6 represent the influence coefficient of compression property of each layer of in-situ improved soil slope in compression property test, F4, F5, F6 respectively represent the evaluation of mechanical properties of each layer of in-situ improved soil slope, s4, s5, s6 respectively represent the influence coefficient of each layer of in-situ improved soil slope.

8. The method for evaluating the damage of acid rain to lime-improved loess according to claim 6, characterized in that: The specific formula for the physical property test evaluation parameter W' of the in-situ improved soil slope is: W′=s4W4×s5W5×s6W6; s4+s5+s6=1; Among them, ρ d-4 , d-5 , d-6 They represent the dry density of each layer of in-situ improved soil slope, e4, e5, e6 represent the void ratio of each layer of in-situ improved soil slope, I4, I5, I6 represent the plasticity index of each layer of in-situ improved soil slope, ρ d-t represents the dry density of the initial improved soil experimentally measured, e t represents the void ratio measured by the initial improved soil experiment, I t represents the plasticity index of the initial improved soil experimentally measured, ρ d-0 represents the dry density measured by the initial loess experiment, e0 represents the porosity ratio measured by the initial loess experiment, I0 represents the plasticity index measured by the initial loess experiment, ρ4, ρ5, ρ6 represent the dry density influence coefficients of each layer of in-situ improved soil slope in the physical property test, ∈4, ∈5, ∈6 represent the porosity influence coefficients of each layer of in-situ improved soil slope in the physical property test, i4, i5, i6 represent the plasticity index influence coefficients of each layer of in-situ improved soil slope in the physical property test, W4, W5, W6 represent the evaluation of the physical properties of each layer of in-situ improved soil slope, s4, s5, s6 represent the influence coefficients of each layer of in-situ improved soil slope.

9. The method for evaluating the damage of acid rain to lime-improved loess according to claim 6, characterized in that: The specific formula for the chemical property test evaluation parameter H' of the in-situ improved soil slope is: H′=s4H4×s5H5×s6H6; s4+s5+s6=1; Among them, ph4, ph5, and ph6 represent the pH values ​​of each layer of in-situ improved soil slope, N SO-4 、N SO-5 、N SO-6 Represents the in-situ improved soil slope of each layer Concentration, N OH-4 、N OH-5 、N OH-6 represents the OH of each layer of in-situ improved soil slope - Concentration, N Ca-4 、N Ca-5 、N Ca-6 represents the Ca of each layer of in-situ improved soil slope 2+ Concentration, pH t represents the pH value measured in the initial improved soil experiment, N SO-t It represents the initial improved soil experimental measurement Concentration, N OH-t represents the OH measured in the initial improved soil experiment - Concentration, N Ca-t represents the Ca content of the initial improved soil experimentally measured 2+ concentration, ph0 represents the pH value measured in the initial loess experiment, N SO-0 The initial loess test results are Concentration, N OH-0 represents the OH measured in the initial loess experiment - Concentration, N Ca-0 represents the Ca content measured in the initial loess experiment 2+ concentration, g4, g5, and g6 represent the concentration of each layer of in-situ improved soil slope in the chemical property test. The ion concentration influence coefficients, a4, a5, and a6 represent the OH concentration of each layer of in-situ improved soil slope in the chemical property test. - The ion concentration influence coefficient of o4, o5, and o6 represent the Ca concentration of each layer of in-situ improved soil slope in the chemical property test. 2+ n4, n5, n6 represent the influence coefficients of main ion concentrations of each layer of in situ improved soil slope in the chemical property test, p4, p5, p6 represent the influence coefficients of pH value of each layer of in situ improved soil slope in the chemical property test, H4, H5, H6 represent the evaluation of the chemical properties of each layer of in situ improved soil slope, s4, s5, s6 represent the influence coefficients of each layer of in situ improved soil slope.

10. A device for evaluating the damage of acid rain to lime-modified loess, characterized in that: The device is applied to the method for evaluating the damage of acid rain to lime-modified loess as claimed in claim 1, and comprises a model test box (1), wherein the model test box (1) is filled with in-situ loess (2) and improved loess slope (3) in sequence from bottom to top, a cavity (4) is arranged between the improved loess slope (3) and the model test box (1), a rainwater outlet (5) connected to the cavity (4) is opened on one side of the model test box (1), a plurality of measuring points (6) are arranged on the upper side of the improved loess slope (3), a laser displacement sensor (7) corresponding to the plurality of measuring points (6) is arranged on the top of the model test box (1), a rainfall simulator (8) is installed on the top of the model test box (1), a water inlet pipe (9) and a water outlet pipe (10) are arranged on the bottom of the model test box (1), a groundwater level detector (11) is arranged on the inner side of the model test box (1), and a temperature controller (12) is arranged on the outer side of the model test box (1); The rainfall simulator (8) is used to simulate acid rain precipitation under different conditions; The measuring points (6) are used to detect various data of the improved loess slope (3); The laser displacement sensor (7) is used to detect the height of the improved loess slope (3) at the measuring point (6) before and after rainfall.

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