Post-occupancy evaluation of the urban underground complex: A case study of Chengdu Tianfu Square in China

Figures & data

Figure 1. Site and built environment of the Tianfu Square UUC.

Figure 2. Underground commercial plan and photographs of the Tianfu Square UUC.

Table 1. Results of KMO Test and the Bartlett’s Test of Sphericity for the field questionnaires.

KMO Test and the Bartlett’s Test of Sphericity
KMO Measure of Sampling Adequacy		.914
Bartlett Test of Sphericity	Approx. Chi-Square	4638.659
	df	496
	Sig.	.000

Table 2. Respondents’ profile based on the online questionnaire.

		N	%
Gender	Male	191	46.02
	Female	224	53.98
Age(years)	<20	6	1.45
	20–29	171	41.20
	30–39	162	39.04
	40–49	47	11.33
	50–59	20	4.82
	>60	9	2.17
Occupation	Employee	179	43.13
	Middle-level cadre or manager	96	23.13
	Teacher	14	3.37
	Student	23	5.54
	Government staff	15	3.61
	Worker	7	1.69
	Self-employed or freelancer	32	7.71
	Retired	9	2.17
	Others	40	9.64
Education	Junior high school	16	3.86
	Senior high school	17	4.10
	Junior college	69	16.63
	Undergraduate	265	63.86
	Master or above	48	11.57

Table 3. Respondents’ satisfaction level of UUCs been built based on the online questionnaire.

Degree of satisfaction	N	%
Very satisfied	79	19.04
Satisfied	221	53.25
Moderately satisfied	93	22.41
Dissatisfied	15	3.61
Very dissatisfied	7	1.69

N = 415.

Table 4. Major problems mentioned and frequency by users based on the online questionnaire.

Major problems	N	%
Insufficient or inconvenient service facilities (toilets, seats, trash cans, consultation desks, etc.)	153	36.87
Ground level entrances are not obvious and are inconsistent with the surrounding environment	142	34.22
Unreasonable scale, lack of vitality, or overcrowding	135	32.53
Poor indoor air and ventilation quality	115	27.71
Remotely situated, inconvenient, and few traffic lines to get here	107	25.78
Poor orientation, unclear signage system, easy to get lost, etc.	99	23.86
Inconvenient public parking	87	20.96
Unreasonable and inconvenient function configuration	87	20.96
Loud noise	82	19.76
Inconvenient transfers inside the UUC	82	19.76
Unreasonable organization of traffic flow (the walking distance is too long, the elevator cannot be found, etc.)	70	16.87
The internal environment lacks natural light and green elements	63	15.18
The internal environment lacks personality and cultural connotations	59	14.22
Insufficient or inconvenient barrier-free facilities	60	14.46
The internal space scale is not comfortable	43	10.36
Poor indoor lighting	40	9.64
Poor indoor air conditioning	27	6.51
The broadcast is not clear and safety promotion is not effective	28	6.75

N = 415.

Table 5. Major factors affecting users’ experience and frequency based on the online questionnaire.

Factors	N	%
Transport convenience and transfer efficiency (convenience of reaching the UUC, efficiency of internal transfer, etc.)	283	68.19
Layout of functions (functional layout, vertical organization, diversity of functions)	214	51.57
Service facilities (commercial and public facilities, barrier-free facilities, consulting services, guiding facilities, etc.)	198	47.71
Orientation (legibility, recognizability, and identity of space)	197	47.47
Internal psychological environment (the proportion of space, comfort, characteristics, culture elements, etc.)	187	45.06
Organization of traffic flows (walking, parking, and vertical transit facilities, such as escalators and elevators)	170	40.96
Physical environment (natural light, landscape and greenery, air quality, sound, light, thermal environment, etc.)	132	31.81
Safe operation and management (evacuation and safety design, security status, safety signs and broadcast effectiveness, management status)	123	29.64

N = 415.

Table 6. Major problems mentioned by the staff interview.

Transportation convenience and transfer efficiency	The main purpose of users coming to the Tianfu Square UUC is to transfer, so the transfer efficiency is important. In addition, there are currently few bus lines for ground transportation. For tourists, the connection between the UUC and surrounding business districts, park and hotels is weak, which causes inconvenience in travel.
Planning and site selection	Located in the urban center, the UUC is given high value both on tourism and consumption, especially on weekends. It would be better if more space is considered in the early planning stage.
Layout of functions	The commercial freight elevator and the passenger elevator in the underground parking space are set at the same position, causing traffic cut. Some new metro stations include functions such as convenience stores in the transfer lobby. Due to space shortage in the Tianfu Square UUC, few were set.
Organization of traffic flow	The entrances to the underground commercial street and to the above ground business district look the same. Passengers usually go to the wrong entrance and get lost. The signage systems for each function are not uniform. During holidays or exhibitions, the crowds in the commercial area will occupy the transfer space. It is recommended to consider separate lobby and exits to evacuate the commercial crowds.
Orientation	During peak hours (17:45–18:50), there are not many passengers asking for directions, because most of them are commuters and familiar with the environment. But on holidays, there are always people asking for directions, who travel for consumption and are not familiar with the environment. So, the signage system is very important.
Service facilities	The entrances and exits are equipped with escalators (mainly going up) and stairs. Since there are old communities and schools nearby, the convenience of the elderly and children should be considered. There are not enough elevators and they can’t go directly from the bottom to the top level because the lower part is in the paid area and the upper part is in the non-paid area, which is inconvenient for passengers, especially for the elderly. A large number of intelligent equipment, such as 3D tactile maps are needed.
Internal environment	Feel hot in the indoor environment during summer, maybe due to the large glass ceiling designed in the centre of the Tianfu Square UUC. There are noise affecting their work. The interior is not bright enough. The height of the space is slightly insufficient. The design of the escalator and stairs only considers evacuation requirements, and does not make full use of space between the columns, resulting in dead ends and waste of space. It is also inconvenient to renovate. The cultural elements need to be improved.
Safety operation and management	the requirements of employees are ignored, because more space is reserved for commercial functions. Once there is an emergency, the evacuation of passengers will be affected. Need to pay more attention to the stability of the equipment, and replace old equipment in time.

Table 7. Frequently mentioned factors affecting the users’ experience of the Tianfu Square UUC (staff perspective).

Factors	N	Description
Transport convenience and transfer efficiency	9	Transport convenience, transfer efficiency
Internal environment	6	Comfort of public areas, physical environment, lack of light, poor indoor air quality, the space feels tight, lack of historic and cultural elements
Service facilities	5	Equipment stability and capability
Safety operation and management	5	The elevator safety, different departments have different safety standards, which makes it difficult to coordinate, poor management
Layout of functions	4	Diversity of functions, the users’ convenience
Orientation	4	Unreasonable, difficult to find directions, easy to get lost
Planning and site selection	3	Location of the UUC

Table 8. Respondents’ profile based on the field questionnaire.

		N	%
Gender	Male	202	50.12
	Female	201	49.88
Age(years)	<20	70	17.37
	20–29	140	34.74
	30–39	49	12.16
	40–49	50	12.41
	50–59	49	12.16
	>60	45	11.17
Occupation	Employee	107	26.55
	Middle-level cadre or manager	24	5.96
	Teacher	12	2.98
	Student	107	26.55
	Government staff	5	1.24
	Worker	15	3.72
	Self-employed or freelancer	52	12.90
	Retired	51	12.66
	Others	30	7.44
Education	Junior high school	85	21.09
	Senior high school	88	21.84
	Junior college	96	23.82
	Undergraduate	118	29.28
	Master or above	16	3.97

Figure 3. Main travel purposes of respondents.

Figure 4. Travel time of respondents.

Figure 5. Main travel mode of respondents.

Figure 6. Travel frequency of respondents.

Figure 7. Duration of usage of respondents.

Table 9. The satisfaction results and their correlation with the overall satisfaction score based on the field questionnaire.

No.	Factors	Min	Max	Mean	S.D.	Correlation with overall satisfaction evaluation
X1	Overall planning	1	5	4.40	0.65	.405**
X2	Scale	2	5	4.20	0.76	.366**
X3	Coordination with the function of the surrounding area	2	5	4.23	0.74	.331**
X4	Coordination with the surrounding environment	2	5	4.26	0.73	.334**
X5	Accessibility of using public transport to the UUC	1	5	4.44	0.73	.092
X6	Accessibility of walking to the UUC	1	5	3.98	0.93	.236**
X7	Diversity of functions	2	5	4.20	0.76	.383**
X8	Configuration of functions	2	5	4.15	0.76	.329**
X9	The layout of the transport space	2	5	4.18	0.76	.316**
X10	The layout of commercial, leisure, entertainment, culture and exhibition spaces	1	5	4.28	0.77	.383**
X11	Vertical organization of functions	1	5	4.07	0.78	.361**
X12	Access facilities (stairs, escalators, elevators, barrier-free facilities, etc.)	2	5	4.31	0.73	.279**
X13	Public service facilities (relaxing, orientation, consultation desk, etc.)	1	5	4.13	0.87	.323**
X14	Convenience of traffic flow organization	1	5	4.28	0.75	.340**
X15	Convenience of commercial flow organization	1	5	4.21	0.74	.314**
X16	Convenience of transfer flow organization	1	5	4.31	0.76	.271**
X17	Openness and identity of the ground level entrances and exits	1	5	3.94	0.88	.346**
X18	Visibility of node spaces such as atriums	2	5	3.95	0.79	.279**
X19	The difference between internal spaces	2	5	3.90	0.78	.369**
X20	The understandability of the internal space	1	5	3.94	0.85	.348**
X21	Identity of the signage system	1	5	3.94	0.92	.359**
X22	The effect of natural light	1	5	4.15	0.85	.383**
X23	The effect of artificial lighting	2	5	4.25	0.75	.279**
X24	Air quality	1	5	3.93	0.83	.380**
X25	Acoustic environment	1	5	3.70	0.94	.349**
X26	Temperature	1	5	4.10	0.80	.354**
X27	Landscape and greenery	1	5	3.81	0.93	.331**
X28	Spatial proportions	1	5	4.03	0.79	.441**
X29	Spatial morphology and texture	1	5	4.01	0.82	.443**
X30	Color, decoration, and materials	1	5	4.05	0.82	.429**
X31	Regional and cultural element of the internal environment	1	5	4.10	0.85	.396**
X32	Security service	1	5	4.32	0.77	.346**
X33	Safety sign and broadcast effectiveness	2	5	4.23	0.76	.394**
X34	Consulting, guidance, and service	1	5	4.07	0.88	.390**
X35	Sanitary conditions	1	5	4.17	0.81	.365**
	Your overall satisfaction	2	5	4.09	0.60

**Correlation is significant at the 0.01 level (2-tailed).

*Correlation is significant at the 0.05 level (2-tailed).

Table 10. The result of multicollinearity test based on the field questionnaire.

Factor	X1	X2	X3	X4	X5	X6	X7	X8	X9	X10	X11	X12	X13	X14	X15	X6	X17	X18
VIF	2.004	1.799	1.754	1.934	1.248	1.316	1.894	2.039	1.743	1.909	1.709	1.469	1.547	1.893	1.962	1.723	1.599	1.569
tolerance	0.499	0.556	0.57	0.517	0.801	0.76	0.528	0.491	0.574	0.524	0.585	0.681	0.647	0.528	0.51	0.58	0.625	0.637
Factor	X19	X20	X21	X22	X23	X24	X25	X26	X27	X28	X29	X30	X31	X32	X33	X34	X35
VIF	1.805	1.758	1.812	1.798	1.644	1.763	1.734	1.628	1.709	2.236	2.509	1.833	1.714	1.709	1.701	1.703	1.489
tolerance	0.554	0.569	0.552	0.556	0.608	0.567	0.577	0.614	0.585	0.447	0.399	0.546	0.583	0.585	0.588	0.587	0.672

a. Dependent variable: the users’ overall satisfaction level.

Table 11. Total variance explained based on the field questionnaire.

Factor	Initial eigenvalues			Extraction sums of squared loadings			Rotation sums of squared loadings
	Total	% of Variance	Cumulative %	Total	% of Variance	Cumulative %	Total	% of Variance	Cumulative %
1	9.211	28.784	28.784	9.211	28.784	28.784	3.007	9.398	9.398
2	2.053	6.415	35.199	2.053	6.415	35.199	2.821	8.817	18.215
3	1.743	5.446	40.644	1.743	5.446	40.644	2.799	8.746	26.961
4	1.473	4.603	45.247	1.473	4.603	45.247	2.683	8.384	35.345
5	1.392	4.349	49.597	1.392	4.349	49.597	2.490	7.781	43.126
6	1.212	3.787	53.384	1.212	3.787	53.384	2.138	6.681	49.807
7	1.086	3.395	56.779	1.086	3.395	56.779	1.747	5.458	55.265
8	1.047	3.272	60.051	1.047	3.272	60.051	1.531	4.786	60.051

Table 12. Rotated factor matrix.

Name	Factors
1) Visual and atmosphere factor	X29. (Spatial morphology and texture)
	X23. (The effect of artificial lighting)
	X30. (Color, decoration, and materials)
	X22. (The effect of natural light)
	X28. (Spatial proportions)
	X31. (Regional and cultural element of the internal environment)
2) Site selection factor	X4. (Coordination with the surrounding environment)
	X3. (Coordination with the function of the surrounding area)
	X1. (Overall planning)
	X2. (Scale)
3) Orientation factor	X20. (The understandability of the internal space)
	X18. (Visibility of node spaces such as atriums)
	X17. (Openness and identity of the ground level entrances and exits)
	X19. (The difference between internal spaces)
	X21. (Identity of the signage system)
4) Functional factor	X9. (The layout of the transport space)
	X7. (Diversity of functions)
	X8. (Configuration of functions)
	X10. (The layout of commercial, leisure, entertainment, culture and exhibition spaces)
5) Physical environment factor	X25. (Acoustic environment)
	X26. (Temperature)
	X27. (Landscape and greenery)
	X24. (Air quality)
	X35. (Sanitary conditions)
6) Safety management factor	X33. (Safety sign and broadcast effectiveness)
	X32. (Security service)
	X34. (Consulting, guidance, and service)
7) Traffic organization factor	X16. (Convenience of transfer flow organization)
	X14. (Convenience of traffic flow organization)
	X5. (Accessibility of using public transport to the UUC)
8) Service facility factor	X13. (Public service facilities: relaxing, orientation, consultation desk, etc.)
	X12. (Access facilities: stairs, escalators, elevators, barrier-free facilities, etc.)