A building developed by Wuhan Shimao Group in Wuhan, China, is a highrise residence with 56 stories near the Yangtze River. The building is a reinforced concrete structure, featuring with a nonregular Ttype plane and a height 179.6 m, which is out of the restrictions specified by the China Technical Specification for Concrete Structures of Tall Building (JGJ32010). To investigate its seismic performance, a shaking table test with a 1/30 scale model is carried out in Structural Laboratory in Wuhan University of Technology. The dynamic characteristics and the responses of the model subject to different seismic intensities are investigated via the analyzing of shaking table test data and the observed cracking pattern of the scaled model. Finite element analysis of the shaking table model is also established, and the results are coincident well with the test. An autoregressive method is also presented to identify the damage of the structure after suffering from different waves, and the results coincide well with the test and numerical simulation. The shaking table model test, numerical analysis, and damage identification prove that this building is well designed and can be safely put into use. Suggestions and measures to improve the seismic performance of structures are also presented.
With the fast urbanization in China, the population growth in cities has led to everincreasing demand for highrise buildings to accommodate commercial and residential needs. Highrise buildings are very common in the densely populated cities all over the world, such as New York and London [
The shaking table test is one of the most widely used techniques to assess the seismic performance of structures made of various materials. Commonly, it is widely used for assessing linear/nonlinear and elastic/inelastic dynamic response of structures. Martinelli et al. [
In shaking table tests, most researchers used scaled models as specimens. For example, Liu et al. [
The above literature review suggests that the shaking table test is an essential tool to assess and verify the dynamic behavior of structures. It is particularly imperative for those structures that exceed the limits of the specification of design codes and standards. It is with this regard that the present paper is in order. The Shimao Building (numbered 1–3 in the A2 block) is an iconic building in the central business district area of Wuhan, China, located on the bank of Yangtze River. It is a combined commercial and residential building with 56 stories. The lateralforce resisting system of the structure is the reinforced concrete (RC) shear wall with a height of 179.6 m, exceeding the limit for highrise buildings specified by Chinese Regulation Technical Specification for Concrete Structures of Tall Building (JGJ32010) [
This paper focuses on the investigation of the seismic behavior of Shimao Building. Firstly, the results of a shaking table test on the 1/30 scale building model will be presented. The structural dynamic characteristics and the responses under different levels of earthquake loading will be investigated, and the failure mechanism and cracking pattern of the tested model will also be obtained. Then, the corresponding finite element model will be established to analyze its seismic performance. At last, a damage identification method based on the autoregressive (AR) model will also be presented to identify the damage of the test building. According to the analysis of experiment, finite element model, and theoretical identification of the test building, seismic performance of the prototype building will be obtained, and this study can make sure that the prototype building is designed reasonably and can be put into use safely. Finally, suggestions and measures to improve the prototype building seismic performance will also be presented.
A 1/30 model of Shimao Building was designed and built for the shaking table test to represent the main characteristics of the prototype building. The experiment was undertaken in the laboratory of School of Civil Engineering and Architecture at Wuhan University of Technology, China. Figure
Sketch of prototype building: (a) elevation view; (b) floor plan below the 41^{st} story (units: mm).
According to the “Technical Points (No. 65, 2015) of Special Inspection for Seismic Fortification of OutofCode Highrise Buildings” [
Dynamic characteristics of the prototype building were calculated through Chinese structural design software PKPM. Although the maximum seismic responses of the structure under Frequent 6 (defined at Section
Dynamic characteristics and seismic response of the prototype building.
Direction  Maximum lateral stiffness (kN/m)  Frequencies (Hz)  Maximum displacement (mm)  Story drift  Torsion displacement ratio 


1.09 × 10^{8}  2.9303  37.72  1/3500  1.15 

1.09 × 10^{8}  3.5724  54.16  1/2359  1.19 
Torsion  1.7173 
In this paper, the similitude law is determined by the dimensional analysis method [
Considering the shaking table size and the height requirement of the laboratory, the dimension scaling parameter
Similitude law.
Contents  Physical quantity  Similitude equation  Similitude law 

Geometric relationship  Length 

1/30 
Linear displacement 

1/30  
Area 

1/900  
Angular displacement  1  1  
Material relationship  Elastic modulus 

1/3.05 
Concrete strength 

1/6.92  
Equivalent mass 

1/13202.6  
Equivalent density 

2.045  
Dynamic relationship  Period 

0.083 
Frequency 

12.012  
Acceleration 

4.81  
Acceleration of gravity 

1  
Force 

1/2745 
Since the aim of the shaking table test is to investigate the seismic behavior of the original structure subjected to different intensity of earthquakes, including failure mode and mechanisms, it is necessary to use the same materials as the prototype building. The materials used for model construction (specimen) are microconcrete (mix proportion is shown in Table
Microconcrete mix proportion.
Intensity level  Position  Mix proportion 

M10  1^{st}∼17^{th} floor  1 : 6.1 : 0.8 
M8  18^{th}∼37^{th} floor  1 : 5.6 : 0.8 
M6  38^{th}∼top floor  1 : 5.0 : 0.8 
Elastic modulus of materials.
Floor  Prototype building (×10^{4} N/mm^{2})  Test model (×10^{4} N/mm^{2})  Ratio 

1^{st}∼7^{th}  3.55  1.21  1/2.93 
8^{th}∼17^{th}  3.45  1.21  1/2.85 
18^{th}∼27^{th}  3.35  1.09  1/3.07 
28^{th}∼37^{th}  3.25  1.09  1/2.98 
38^{th}∼46^{th}  3.15  0.95  1/3.32 
47^{th}∼top floor  3.00  0.95  1/3.16 
Pictures of the model: (a) model under construction; (b) completed model.
The test variables include two types: different fortification intensity and different types of earthquake waves. According to related researches on the statistics of the peak acceleration of ground motions in China, the seismic intensity of a specific site exhibits the extreme distribution of the III type (Weibull distribution). The fortification intensity is defined as the intensity with 10% exceedance probability, which is also called as the moderate or basic intensity for simplicity. Similarly, the rare and frequent intensity is defined as the intensity with 2–3% and 65% exceedance probability, respectively. Furthermore, for the moderate intensity of a specific site, the frequent and rare intensity is about 1.55° lower and 1° higher than the moderate intensity, respectively. In this paper, the scaled building under investigation is located in Wuhan with Degree 6 as the fortification/basic intensity [
According to the dynamic characteristics and site condition of the prototype structure, three seismic runs are chosen for simulating the shaking table test input wave: (1) El Centro wave, with a peak acceleration of 3.41 m/s^{2}; (2) Taft wave, with a peak acceleration of 1.53 m/s^{2}; and (3) artificial seismic wave (USER1), supplied by the construction designers, with a peak acceleration of 0.18 m/s^{2}. The timehistory curves are shown in Figure
Input seismic loading sequence: (a) El Centro wave; (b) Taft wave; (c) artificial seismic wave.
Characteristics of the shaking table.
Item  Parameter 

Table size  3 × 3 m 
Vibrating direction  One dimensional 
Maximum displacement  ±100 mm 
Maximum velocity  500 mm/s 
Maximum acceleration  ±2.0 g (no load); ±1.3 g (full load) 
Maximum model mass  10 t 
Frequency range  0.4∼40 Hz 
The testing procedure is shown in Table
Sequence of the shaking table test.
Test condition  Sequence number  Input seismic wave 

Frequent 6  1  White noise 
2  El Centro wave  
3  Taft wave  
4  Artificial seismic wave  


Moderate 6  5  White noise 
6  El Centro wave  
7  Taft wave  
8  Artificial seismic wave  


Rare 6  9  White noise 
10  El Centro wave  
11  Taft wave  
12  Artificial seismic wave  


Rare 7  13  White noise 
14  El Centro wave  
15  Taft wave  
16  White noise 
The main measurement of structural response is acceleration, displacement, strain, etc. Several acceleration sensors, displacement sensors, and strain gauges are arranged at the different heights of the model to measure the responses of the model structure under different seismic fortification intensities. Accelerations and displacements were measured by the large dynamic signal acquisition and analysis system DASP2003, developed by Orient Institute of Noise and Vibration. 14 acceleration sensors were used for different purposes, namely, 2 for measuring vertical accelerations, 10 for horizontal accelerations, and 2 for torsion of the building. Dynamic strain was obtained by the dynamic and static testing instrument DH3817. Five displacement sensors were used to measure the deformation along the direction of shaking. The positions of acceleration sensors and displacement sensors are shown in Figure
Positions of sensors: (a) acceleration sensors; (b) displacement sensors.
When subjected to Frequent 6, there were no noticeable shaking and visible damages, it can be predicted that the test model can remain in a serviceable condition after Frequent 6, and there was no damage. In the case of Moderate 6, the model responded with little vibration, but no cracks and structural damages, which may indicate that the model is still in serviceable conditions, and there was no need to strengthen. No visible cracks and significant damages occurred after Rare 6. However, the model responded with more vibrations and little crack, which indicated that the model was minor damaged, even though the test building was still in the serviceable condition. Some part of it might need to be repaired. When subjected to Rare 7, it is observed that the model vibrates significantly, together with a large number of cracks in the upper part of the model and spalling of concrete. It can be concluded that the test building is not collapsed even when subject to Rare 7 but lost much of its lateral load resisting capacity. Since the prototype building is represented as the model, the damage pattern of the prototype building can be obtained. The damage of different floors after the test is shown in Figure
Damages of the test model after seismic input: (a) floors 1 to 3; (b) 42^{nd} floor; (c) 52^{nd} floor.
Low peak white noise excitation was used before and after seismic excitation for capturing the dynamic characteristic of the model. Results are shown in Table
Dynamic characteristic of the model before and after the earthquake excitation.
Earthquake intensity  Test items 

Torsion 



1^{st} order  2^{nd} order  3^{rd} order  1^{st} order  2^{nd} order  3^{rd} order  
Before earthquake  Frequency (Hz)  2.54  12.11  29.41  7.62  21.30  3.71 
Period (s)  0.3937  0.0826  0.0340  0.1312  0.0469  0.2695  
Damping ratio (%)  3.25  2.61  2.12  2.36  


Frequent 6  Frequency (Hz)  2.54  12.11  29.21  7.62  21.10  
Period (s)  0.3937  0.0826  0.0342  0.1312  0.0474  
Damping ratio (%)  4.41  2.71  2.83  


Moderate 6  Frequency (Hz)  2.54  11.92  28.72  7.52  20.91  
Period (s)  0.3937  0.0839  0.0348  0.1330  0.0478  
Damping ratio (%)  4.20  3.04  3.37  


Rare 6  Frequency (Hz)  2.44  11.33  27.75  7.30  19.93  
Period (s)  0.4098  0.0883  0.0360  0.1370  0.0502  
Damping ratio (%)  4.01  3.11  3.35  


Rare 7  Frequency (Hz)  2.34  10.75  6.84  18.66  
Period (s)  0.4274  0.0930  0.1462  0.0536  
Damping ratio (%)  3.87  3.80 
Acceleration amplification factor is the ratio of the maximum absolute value of acceleration response of each story to the maximum input acceleration at the bottom of the model. This factor is of great significance to analyze the seismic performance of structures, describing how many times the accelerations at each story are amplified compared to the base seismic excitation. Hence, the acceleration amplification factor can be obtained through dividing the peak accelerations of the testing stories by the peak accelerations of the shaking table in this test. Then, the envelope diagram of the building in different test conditions can be drawn. Figure
Envelope of acceleration amplification factor under different earthquake levels: (a) El Centro seismic excitation; (b) Taft seismic excitation; (c) artificial seismic wave (USER1).
Peak acceleration and acceleration amplification factors.
Floor  El Centro wave  Taft wave  Artificial seismic wave  








Frequent 6  1^{st}  0.399  1.000  0.441  1.000  0.704  1.000 
14^{th}  1.223  3.061  0.889  2.013  1.443  2.050  
28^{th}  0.870  2.179  1.038  2.351  1.360  1.932  
41^{st}  0.884  2.214  0.939  2.127  1.169  1.660  
50^{th}  0.643  1.610  0.628  1.422  1.006  1.429  
Top floor  1.626  4.071  1.483  3.358  1.850  2.628  
Roof  2.027  5.076  1.898  4.298  2.124  3.016  


Moderate 6  1^{st}  0.569  1.000  0.648  1.000  0.952  1.000 
14^{th}  1.710  3.005  1.331  2.054  1.502  1.578  
28^{th}  1.229  2.160  1.397  2.155  1.787  1.877  
41^{st}  1.239  2.177  1.310  2.022  1.405  1.476  
50^{th}  0.824  1.448  0.845  1.304  1.387  1.456  
Top floor  2.206  3.876  2.139  3.301  2.607  2.738  
Roof  2.678  4.705  2.680  4.135  2.792  2.932  


Rare 6  1^{st}  0.921  1.000  1.100  1.000  1.475  1.000 
14^{th}  1.219  1.323  1.881  1.710  2.192  1.486  
28^{th}  1.484  1.611  1.965  1.786  2.925  1.982  
41^{st}  1.400  1.521  2.122  1.929  2.090  1.416  
50^{th}  1.217  1.322  1.590  1.445  2.371  1.607  
Top floor  2.212  2.402  2.962  2.692  3.973  2.693  
Roof  3.022  3.281  3.358  3.052  4.066  2.756 
As can be seen, the acceleration amplification factors along the floors of the structure are nearly invariable except for the top floor, reflecting the lateral stiffness at different floors (except for the top floor) is uniformly distributed. Furthermore, the acceleration amplification factor was almost unchanged after suffering from Frequent and Moderate 6, which indicated that the lateralforce resisting components of the model are seldom damaged. However, the acceleration amplification factor increases sharply on the top floor and roofing layer, indicating that the whiplash effect cannot be ignored in this case. Usually when damages are increasing, the stiffness of structures is reducing, leading to the elasticplastic phrase, which can result in a smaller acceleration amplification. It can be seen in Figure
The displacement response of the model was converted to the displacement response of the prototype by a similar law. The formula to translate the maximum displacement response from the test model to the prototype building should be as follows:
The maximum displacement and corresponding displacement angle of the prototype structure’s roof under different seismic levels are listed in Table
Maximum displacement and displacement angle of the roof of the prototype building.
Seismic intensity  Test condition  Seismic wave  Displacement of vertex (m)  Displacement angle of vertex 

Frequent 6  Condition 2  El Centro wave 
0.016  1/4654 
Condition 3  Taft wave 
0.010  1/7670  
Condition 4  Artificial seismic wave 
0.008  1/9848  


Moderate 6  Condition 6  El Centro wave 
0.043  1/1573 
Condition 7  Taft wave 
0.026  1/2642  
Condition 8  Artificial seismic wave 
0.023  1/2932  


Rare 6  Condition 10  El Centro wave 
0.060  1/953 
Condition 11  Taft wave 
0.048  1/1196  
Condition 12  Artificial seismic wave 
0.052  1/1110  


Rare 7  Condition 14  El Centro wave 
0.139  1/456 
Condition 15  Taft wave 
0.144  1/439 
Figure
Envelope of relative displacement under different earthquake levels: (a) Frequent 6; (b) Moderate 6; (c) Rare 6; (d) Rare 7.
The story drift of representative floors under different seismic waves is listed in Table
Story drift of the structure under different seismic waves.
Seismic intensity  Seismic wave  20^{th} floor  41^{st} floor  56^{th} floor (top) 

Frequent 6  El Centro  0.045  0.069  0.159 
Taft  0.039  0.06  0.096  
Artificial  0.039  0.054  0.075  


Moderate 6  El Centro  0.141  0.189  0.432 
Taft  0.099  0.165  0.258  
Artificial  0.099  0.177  0.234  


Rare 6  El Centro  0.255  0.324  0.603 
Taft  0.219  0.351  0.48  
Artificial  0.276  0.384  0.519 
There are symmetrical accelerometers arranged at the 41^{st} and the top floor. The displacements under different seismic intensities of these two stories can be obtained by integrating the accelerations. Hence, the torsion can be obtained by the ratios of the displacements to the sensors’ distances. Torsion angle of the model under different seismic levels is shown in Figure
Torsion angle under different floors: (a) 41^{st} floor; (b) 51^{st} floor.
According to transformation formula, the hysteresis curve of the prototype structure under different earthquake levels can be obtained by the displacement historical response and shear historical responses. The shear responses can be calculated by quality distribution of floors and corresponding acceleration responses. Taking Rare 6 as an example, considering the limited pages of this paper, the hysteresis curve under different waves is shown in Figure
Hysteresis curve of the prototype structure under different waves: (a) El Centro wave; (b) Taft wave; (c) artificial seismic wave.
In order to verify the experimental results, a finite element model of the test model was established by ANSYS. Elasticplastic analysis of the test model was conducted. Threedimensional BEAM4 element was used to simulate the beams and embedded columns, and SHELL63 was used to simulate the floors and shear walls. The material properties were obtained from the measured tests, and the nonlinear performance of materials had been considered. The input seismic waves used in the finite element model were the same as the shaking table test. Real properties of the materials of the model had been taken into account. The finite element mode contained 78899 nodes, beam elements 4599, and shell elements 72414 totally. The height is 179.4 m, which is the same as the prototype building.
The results of the finite element analysis indicate that first three order vibration modes of the model include the translation mode in
First three vibration modes: (a) 1^{st} (
Table
Comparison of free vibration characteristics.
Vibration mode  Experimental result  Finite element result  

Frequency (Hz)  Period (s)  Frequency (Hz)  Period (s)  

1^{st} order  2.54  0.3937  2.5348  0.394 
2^{nd} order  12.11  0.0826  9.7863  0.102  



1^{st} order  3.71  0.2695  3.8012  0.263 
2^{nd} order  —  —  12.833  0.077  


Torsion  1^{st} order  7.62  0.1312  6.6293  0.151 
2^{nd} order  21.30  0.0469  27.641  0.036 
Table
Comparison of maximum acceleration amplification factor in the
Seismic intensity  Input seismic wave  Maximum acceleration amplification factor  

Experimental value  Numerical value  
Frequent 6  El Centro  5.90  5.34 
Taft  5.46  5.13  
Artificial  4.94  4.68  


Moderate 6  El Centro  3.83  4.01 
Taft  3.44  3.14  
Artificial  3.16  3.11  


Rare 6  El Centro  3.12  3.26 
Taft  2.29  2.57  
Artificial  2.68  2.48 
It can be seen in Table
In order to compare the experimental results with the calculated results, the maximum displacement of the test floors under different earthquake levels is listed in Table
Comparison of maximum displacements (cm).
Seismic intensity  Seismic wave  20^{th} floor  41^{st} floor  56^{th} floor (top)  

Experimental value  Numerical value  Experimental value  Numerical value  Experimental value  Numerical value  
Frequent 6  El Centro  0.15  0.18  0.23  0.25  0.53  0.64 
Taft  0.13  0.14  0.2  0.22  0.32  0.57  
Artificial  0.13  0.16  0.18  0.19  0.25  0.46  


Moderate 6  El Centro  0.47  0.51  0.63  0.71  1.44  1.52 
Taft  0.33  0.35  0.55  0.65  0.86  1.23  
Artificial  0.33  0.31  0.59  0.62  0.78  1.01  


Rare 6  El Centro  0.85  0.92  1.08  1.12  2.01  2.34 
Taft  0.73  0.80  1.17  1.15  1.6  2.02  
Artificial  0.92  0.88  1.28  1.07  1.73  1.91 
Envelope diagrams of story drift under different earthquake waves: (a) El Centro wave; (b) Taft wave; (c) artificial seismic wave.
It can be calculated that both the story drift angle of the finite element model and test model under Frequent and Moderate 6 can meet the seismic resistance requirements in the code specification (1/800). The maximum story drift angle of the finite element model under Rare 6 is 1/350, which is larger than the limited elastic value; however, it still can meet the requirements of plastic story drift angle in the Chinese code (JGJ32010) [
In this section, an identification method based on the AR model is presented to identify the damage location and degree of the test model after suffering from simulated earthquakes. Firstly, the AR model is briefly introduced and established by the acceleration response of the test model. Secondly, the plain version of the least squares (LS) method is used to solve the unknown parameters of the established AR model. Then, a judging factor based on the residual variance of the AR model is proposed to estimate the degree of structural damage. Finally, the proposed damage factor of the model building after different earthquake intensities is calculated by MATLAB. The damage location and degree identified by this method are compared with the testing results as well as the numerical results.
The AR model is widely used in the field of structural damage identification [
In this paper, a famous approach the least square (LS) method is used to estimate unknown vector
Estimated residual is as follows:
However, finding out the optimal order
After the unknown parameter
Dividing the obtained response acceleration data before damage into two parts, part
Estimating
Dividing all the observed data into part
Calculating the average of
The damage identification factor is calculated as the ratio between the residential variance of
It is clear that if the data to be estimated is coming from the undamaged structure, IF will be close to one. Otherwise,
In this part, the IF of different stories and seismic intensities will be presented. It can be seen in Table
IF of some floors after different earthquake intensities: (a) 1^{st} floor; (b) 8^{th} floor; (c) 41^{st} floor; (d) top floor.
When comparing the damages of all stories after the same seismic intensity, the damage variation along stories can be studied. For the sake of simplicity, Figure
IF along stories: (a) Frequent 6; (b) Rare 7.
It can be concluded that after Frequent 6, all the IF ranges from 1.0 to 1.25, indicating very little damages occurred in the model building. Even though the IF of the 1^{st} floor and top floor is the smallest and largest respectively, there is only a little difference. However, after suffering from Rare 7, the damage increases obviously, the damage degree of 50^{th}, 52^{nd}, and top floors is larger than that of other floors, and the damage of 14^{th}, 28^{th}, and 8^{th} stories is quite significant as well, while the damage of the first story is the smallest. This variation can also be found in Table
Moreover, after studying the IF of the three types of waves used in the test, the variation of IF is nearly the same with that of white noise, and the results will not be detailed here. However, the comparison of the effectiveness between different types of waves cannot be obtained, probably due to no relative data to be used to calculate the healthy residential of benchmark data (
To summarize, we can reach the conclusion that the identification results are reasonable and coincide well with the results of the experiment and numerical simulation, which indicates that the identification method presented here is effective, and not only the location but also the degree of the damage can be identified by the new identification factor.
The prototype building is represented as the testing model in this paper. Based on all the analysis, it can be concluded that after Frequent 6, almost no changes occur in the structure which is still in the elastic stage. After Moderate 6, no visible damages occur, and natural frequency decreased slightly, which indicates that the stiffness of the prototype building was changed slightly in this condition. However, under Rare 6, the 1^{st} natural frequency decreased by 3.9% and other parameters had little of changes, which suggests that some part of the prototype building will be damaged in this condition. Under Rare 7, visible cracks and spalling of concrete occur, and the natural frequency of the model decreased significantly, which means that the prototype building has been damaged significantly in this condition.
Acceleration response of the top part of the structure is relatively large, which indicates that the whiplash effect of the building is significant. The torsional deformation is not apparent when an earthquake is small, but it became more substantial when the level of input earthquake increased, which indicates that the effect of torsion on seismic response of the structure is increased. Furthermore, the effect of torsion is large above the 41^{st} floors, especially on the 52^{nd} floor, showing that these floors may be weaker than other parts relatively. However, as for the same level of earthquake intensity, the maximum displacement, displacement angle, story drift, and torsional angle of the model caused by the El Centro wave are the largest among the three types of input waves, followed by the Taft wave and artificial seismic wave. Thus the El Centro wave may be the most dangerous wave to the prototype building.
Finite element simulation results coincide well with the experimental results. Higher vibration modes of the building show that vibration modes have become localized after 15^{th} order, and the vibration mode of the structure is translationtorsion coupled; the whiplash effect at the top of the structure is quite remarkable.
The damage degree and location identified by the proposed factor in this paper also show that the upper part of the building has more damage than the lower part, but the damage of 8^{th}∼28^{th} floor is also quite significant. With the increase of the earthquake acceleration, the damage of the building increases apparently. The identification results indicate that the identification method is effective and can be used in other similar cases.
The results of the test, the numerical analysis, and the identification prove that the building in the A2 block developed by Wuhan Shimao Group was designed reasonably, which can entirely meet the requirement in the Chinese Code and can be safely put into use. Even though the design of this building can meet the seismic design requirements, some measures should be taken to improve the seismic performances. Firstly, the connection between the shear wall of the bottom floor and the base can be strengthened to avoid horizontal joinedup cracks under big earthquakes. Then, the effect of torsion is large above the 41^{st} floor of the building, but the damage of the 8^{th}∼28^{th} floor cannot be neglected either. More structural reinforcements may be necessary for these floors. The top of the structure also needs to be strengthened since the whiplash effect is obvious.
The data of this study are available from the corresponding author upon request.
The authors declare that there are no conflicts of interest regarding the publication of this paper.
This work was supported by the National Natural Science Foundation of China (NSFC) (grant no. 51678464) and the China Government Scholarship Council (CSC no. 201706950038).