CN-115329274-B - Conversion method between various dynamic sounding test indexes considering multiple collisions

Abstract

The invention discloses a conversion method among various dynamic sounding test indexes considering multiple collisions in the field of geotechnical engineering in-situ tests, which comprises the steps of firstly calculating an acceleration initial value of a soil body to a probe rod, then calculating a drop hammer speed after the ith collision, the probe rod speed and a probe rod kinetic energy increment until the drop hammer speed after the collision is equal to the probe rod speed or the drop hammer speed is equal to 0, stopping calculation, taking the sum of the probe rod kinetic energy increment after each collision and the kinetic energy at the final time of the drop hammer as dynamic sounding effective hammering energy, correcting the acceleration of the soil body to the probe rod by using the dynamic sounding effective hammering energy, correcting the dynamic sounding effective hammering energy by using an iteration method, calculating the dynamic sounding test effective hammering energy before conversion, and calculating the dynamic sounding hammering number after conversion by using an iteration method. The invention can provide guidance for the interconversion among different dynamic sounding test indexes.

Inventors

• SHEN ZHIPING
• LIU HUI
• FU JUNYI
• SUN HONG
• XU FEIZHOU
• ZHANG JIN
• YANG XIN

Assignees

• 贵州正业工程技术投资有限公司
• 贵州正建兴业工程质量检测有限公司

Dates

Publication Date

20260512

Application Date

20220808

Claims (3)

1. 1. The conversion method between various dynamic sounding test indexes considering multiple collisions is characterized by comprising the following steps: step S1, calculating an acceleration a initial value of the soil body to the probe rod by using the following steps: , , wherein M is the falling weight, h is the falling weight distance, M is the probe rod weight, N is the power sounding hammer hit number, l is the probe rod length, M ' is the weight of each linear meter probe rod, and M ' ' is the total weight of the guide rod, the hammer pad and the probe; n is the number of hammering when penetrating 10 cm; step S2, calculating the ratio k of the gravity acceleration g to the acceleration a of the soil body to the probe rod: Step S3, respectively calculating the falling weight speed V 1 and the probe rod speed V 1 after the first collision and the kinetic energy increment delta E 1 of the probe rod after the first collision by using the following steps; , , , wherein e is the collision recovery coefficient of steel used in the dynamic sounding test; Step S4, calculating the falling weight speed V 2,0 before the 2 nd collision and the probe rod speed V 2,0 : , , Wherein, Δv n-1 =V n-1 -v n-1 , n=2, Δv 1 =V 1 -v 1 ; step S5, calculating the post-2 collision drop hammer velocity V 2 and the probe rod velocity V 2 using the following, the probe rod kinetic energy increment Δe 2 in the 2 nd collision, where n=3, , , , Step S6, sequentially updating the n value, repeating the step S4 and the step S5 to obtain the i-th collision post-falling hammer speed V i and the probe rod speed V i , and the probe rod kinetic energy increment delta E i in the i-th collision until V i =v i or V i =0, marking the j-th collision, and ending calculation; Step S7, calculating the kinetic energy in the drop hammer in the final state using the following formula: , wherein V Termination of is the speed of the falling weight when the collision cycle calculation is terminated; step S8, calculating the effective hammering energy of the dynamic sounding by using the following steps: , Step S9, calculating acceleration a according to the following formula, and calculating effective hammering energy E through an iterative method; , the method for calculating the effective hammering energy in the step S9 through an iterative method includes: Bringing the acceleration a obtained in the step S9 into the step S2, sequentially calculating to the step S9, calculating a new acceleration a, bringing the new acceleration a into the step S2, sequentially calculating to the step S9, calculating an updated acceleration a, circularly calculating until the difference value of the acceleration a obtained by two adjacent times of calculation is smaller than a preset difference value, and taking the effective hammering energy obtained by the last calculation as a calculation result of the final effective hammering energy; Step S10, calculating the hammering energy E (M 1 ,m 1 ',m 1 '',l 1 ,N 1 ) before conversion and the hammering energy E (M 2 ,m 2 ',m 2 '',l 2 ,N 2 ) after conversion by utilizing the steps S1-S9, wherein when the hammering energy E (M 2 ,m 2 ',m 2 '',l 2 ,N 2 ) after conversion is calculated for the first time, N 2 =N 1 is caused, and the converted hammering number N 2 obtained by the first iterative calculation is calculated according to the following formula; , wherein A 1 is the cross-sectional area of the probe of the power penetration test before conversion, A 2 is the cross-sectional area of the probe of the power penetration test after conversion, M 1 is the weight of the falling weight of the power penetration test before conversion, M 1 ' is the mass of each linear meter probe before conversion, M 1 ″ is the sum of the mass of the guide rod, the hammer pad and the probe before conversion, l 1 is the length of the probe before conversion, N 1 is the actual measured hammering number before conversion, M 2 is the weight of the falling weight after conversion, M 2 ' is the mass of each linear meter probe after conversion, M 2 ' is the sum of the mass of the guide rod, the hammer pad and the probe after conversion, l 2 is the length of the probe after conversion, and N 2 is the converted hammering number; Step S11, carrying out step S1-S9 on the converted hammering number N 2 obtained by the first iterative calculation, calculating converted hammering energy E (M 2 ,m 2 ',m 2 '',l 2 ,N 2 ), and calculating according to a formula of step S10 to obtain a converted hammering number N 2 obtained by the second iterative calculation; Step S12, carrying out step S1-S9 on the converted hammering number N 2 obtained by the ith iterative computation, calculating converted hammering energy E (M 2 ,m 2 ',m 2 '',l 2 ,N 2 ), and calculating according to a formula of step S10 to obtain the converted hammering number N 2 obtained by the (i+1) iterative computation; and S13, if the converted hammering number obtained by the ith iterative computation is equal to the converted hammering number obtained by the (i+1) iterative computation, ending the cyclic iterative computation, and taking the hammering number obtained by the last computation as the hammering number obtained by final conversion.
2. 2. The method for converting between various dynamic touch test indexes considering multiple collisions according to claim 1, wherein the step S3 further comprises: and obtaining the steel collision recovery coefficient e used in the dynamic sounding test determined by the field test.
3. 3. The method for converting between various dynamic touch test indexes considering multiple collisions according to claim 1, wherein the preset difference is 0.001m/s 2 .

Description

Conversion method between various dynamic sounding test indexes considering multiple collisions Technical Field The invention relates to the field of geotechnical engineering in-situ tests, in particular to a conversion method among various dynamic sounding test indexes considering multiple collisions. Background The cone dynamic sounding test is a geotechnical engineering in-situ test which utilizes a certain hammering kinetic energy to beat a cone probe with a certain specification into soil, judges the change of a soil layer according to the impedance during beating, layers the soil layer, estimates the physical and mechanical property index of the soil layer and identifies the compactness of the soil, and has the characteristics of simplicity, easiness and practicability and wide application in the geotechnical engineering in-situ investigation and detection fields. The conventional multiple types of dynamic sounding equipment are applied to the fields of geotechnical engineering investigation and detection at home and abroad, and have respective evaluation indexes for different types of dynamic sounding equipment, so that comparison analysis cannot be directly carried out among different types of dynamic sounding test results, and various inconveniences are brought to engineering investigation, detection, design and construction. Disclosure of Invention The invention aims to solve the technical problem of providing a conversion method between various dynamic sounding test indexes considering multiple collisions so as to solve the defects in the prior art. In order to achieve the above purpose, the embodiment of the present invention adopts the following technical scheme: the embodiment of the invention provides a conversion method among various dynamic sounding test indexes considering multiple collisions, which comprises the following steps: step S1, calculating an acceleration a initial value of the soil body to the probe rod by using the following steps: m=lm'+m” Wherein M is the falling weight, h is the falling weight distance, M is the probe rod weight, N is the power sounding hammer hit number, l is the probe rod length, M 'is the weight of each linear meter probe rod, and M' is the total weight of the guide rod, the hammer pad and the probe; step S2, calculating the ratio k of the gravity acceleration g to the acceleration a of the soil body to the probe rod: Step S3, respectively calculating the falling weight speed V 1 and the probe rod speed V 1 after the first collision and the kinetic energy increment delta E 1 of the probe rod after the first collision by using the following steps; wherein e is the collision recovery coefficient of steel used in the dynamic sounding test; Step S4, calculating the falling weight speed V 2,0 before the 2 nd collision and the probe rod speed V 2,0: Wherein, Δv n-1＝Vn-1-vn-1, n=2, Δv 1＝V1-v1; step S5, calculating the post-2 collision drop hammer velocity V 2 and the probe rod velocity V 2 using the following, the probe rod kinetic energy increment Δe 2 in the 2 nd collision, where n=3, Step S6, sequentially updating the n value, repeating the step S4 and the step S5 to obtain the i-th collision post-falling hammer speed V i and the probe rod speed V i, and the probe rod kinetic energy increment delta E i in the i-th collision until V i＝vi or V i =0, marking the j-th collision, and ending calculation; Step S7, calculating the kinetic energy in the drop hammer in the final state using the following formula: wherein V Termination of is the speed of the falling weight when the collision cycle calculation is terminated; step S8, calculating the effective hammering energy of the dynamic sounding by using the following steps: Step S9, calculating acceleration a according to the following formula, and calculating effective hammering energy E through an iterative method; Step S10, calculating the hammering energy E (M 1,m1',m1",l1,N1) before conversion and the hammering energy E (M 2,m2',m2",l2,N2) after conversion by utilizing the steps S1-S9, wherein when the hammering energy E (M 2,m2',m2",l2,N2) after conversion is calculated for the first time, N 2＝N1 is caused, and the converted hammering number N 2 obtained by the first iterative calculation is calculated according to the following formula; Wherein A 1 is the cross-sectional area of the probe of the power penetration test before conversion, A 2 is the cross-sectional area of the probe of the power penetration test converted by A 1 is the weight of the falling weight of the power penetration test before conversion, M 1 'is the mass of each linear meter probe before conversion, M 1' is the sum of the mass of the guide rod, the hammer pad and the probe before conversion, l 1 is the length of the probe before conversion, N 1 is the actual measured hammering number before conversion, M 2 is the weight of the falling weight after conversion, M 2 'is the mass of each linear meter probe after conversion, M 2' is the s